133 DBMS_SQL

Using DBMS_SQL

• Overview

• Security Model

• Constants

• Exceptions

• Operational Notes

• Examples

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Overview

Oracle lets you write stored procedures and anonymous PL/SQL blocks that use dynamic SQL. Dynamic SQL statements are not embedded in your source program; rather, they are stored in character strings that are input to, or built by, the program at runtime. This enables you to create more general-purpose procedures. For example, dynamic SQL lets you create a procedure that operates on a table whose name is not known until runtime.

Native Dynamic SQL is an alternative to DBMS_SQL that lets you place dynamic SQL statements directly into PL/SQL blocks. In most situations, Native Dynamic SQL is easier to use and performs better than DBMS_SQL. However, Native Dynamic SQL itself has certain limitations:

• There is no support for so-called Method 4 (for dynamic SQL statements with an unknown number of inputs or outputs)

Also, there are some tasks that can only be performed using DBMS_SQL.

The ability to use dynamic SQL from within stored procedures generally follows the model of the Oracle Call Interface (OCI).

PL/SQL differs somewhat from other common programming languages, such as C. For example, addresses (also called pointers) are not user-visible in PL/SQL. As a result, there are some differences between the Oracle Call Interface and the DBMS_SQL package. These differences include the following:

• The OCI uses bind by address, while the DBMS_SQL package uses bind by value.

• With DBMS_SQL you must call VARIABLE_VALUE to retrieve the value of an OUT parameter for an anonymous block, and you must call COLUMN_VALUE after fetching rows to actually retrieve the values of the columns in the rows into your program.

• The current release of the DBMS_SQL package does not provide CANCEL cursor procedures.

• Indicator variables are not required, because NULLs are fully supported as values of a PL/SQL variable.

A sample usage of the DBMS_SQL package follows. For users of the Oracle Call Interface, this code should seem fairly straightforward.

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Security Model

DBMS_SQL is a SYS-owned package compiled with AUTHID CURRENT_USER. Any DBMS_SQL subprogram called from an anonymous PL/SQL block is run using the privileges of the current user.

In Oracle Database 11g, Release 1 (11.1), Oracle introduces a number of enhancements to DBMS_SQL to improve the security of the package.

Preventing Malicious or Accidental Access of Open Cursor Numbers

An error, ORA-29471, is raised when any DBMS_SQL subprogram is called with a cursor number that does not denote an open cursor. When the error is raised, an alert is issued to the alert log and DBMS_SQL becomes inoperable for the life of the session.

If the actual value for the cursor number in a call to the IS_OPEN Function denotes a cursor currently open in the session, the return value is TRUE. If the actual value is NULL, then the return value is FALSE. Otherwise, this raises an ORA-29471 error.

Note that the OPEN_CURSOR Function is the only DBMS_SQL subprogram that has no formal parameter for the cursor number; rather, it returns a cursor number. Therefore it is not within the scope of these rules.

Preventing Inappropriate Use of a Cursor

Cursors are protected from security breaches that subvert known existing cursors.

Checks are made when binding and executing. Optionally, checks may be performed for every single DBMS_SQL subprogram call. The check is:

• The current_user is the same on calling the subprogram as it was on calling the most recent parse.

• The enabled roles on calling the subprogram must be a superset of the enabled roles on calling the most recent parse.

Consistent with the use of definer's rights subprograms, roles do not apply.

If either check fails, and ORA-29470 error is raised.

The mechanism for defining when checks are performed is a new overload for the OPEN_CURSOR subprogram which takes a formal parameter, security_level, with allowed values NULL, 1 and 2.

• When security_level = 1 (or is NULL), the checks are made only when binding and executing.

• When security_level = 2, the checks are always made.

Upgrade Considerations

This security regime is stricter than those in Oracle Database 10g, Release 2 (10.2) and previous releases. As a consequence, users of DBMS_SQL may encounter runtime errors on upgrade. While these security enhancements make for more secure applications, users may wish to relax the security checks temporarily as they migrate to Oracle Database 11g, Release 1 (11.1). If so, please consult with Oracle Support on steps to relax the above security restrictions.

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Constants

The constants described in Table 133-1 are used with the language_flag parameter of the PARSE Procedures.

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Exceptions

inconsistent_type EXCEPTION;
  pragma exception_init(inconsistent_type, -6562);

This exception is raised by the COLUMN_VALUE Procedure or the VARIABLE_VALUE Procedures when the type of the given OUT parameter (for where to put the requested value) is different from the type of the value.

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Operational Notes

• Execution Flow

• Processing Queries

• Processing Updates, Inserts, and Deletes

• Locating Errors

Execution Flow

1. OPEN_CURSOR

2. PARSE

3. BIND_VARIABLE or BIND_ARRAY

4. DEFINE_COLUMN, DEFINE_COLUMN_LONG, or DEFINE_ARRAY

5. EXECUTE

6. FETCH_ROWS or EXECUTE_AND_FETCH

7. VARIABLE_VALUE, COLUMN_VALUE, or COLUMN_VALUE_LONG

8. CLOSE_CURSOR

OPEN_CURSOR

To process a SQL statement, you must have an open cursor. When you call the OPEN_CURSOR Function function, you receive a cursor ID number for the data structure representing a valid cursor maintained by Oracle. These cursors are distinct from cursors defined at the precompiler, OCI, or PL/SQL level, and are used only by the DBMS_SQL package.

PARSE

Every SQL statement must be parsed by calling the PARSE Procedures. Parsing the statement checks the statement's syntax and associates it with the cursor in your program.

You can parse any DML or DDL statement. DDL statements are run on the parse, which performs the implied commit.

The execution flow of DBMS_SQL is shown in Figure 133-1.

BIND_VARIABLE or BIND_ARRAY

Many DML statements require that data in your program be input to Oracle. When you define a SQL statement that contains input data to be supplied at runtime, you must use placeholders in the SQL statement to mark where data must be supplied.

For each placeholder in the SQL statement, you must call one of the bind procedures, the BIND_ARRAY Procedures or the BIND_VARIABLE Procedures, to supply the value of a variable in your program (or the values of an array) to the placeholder. When the SQL statement is subsequently run, Oracle uses the data that your program has placed in the output and input, or bind, variables.

DBMS_SQL can run a DML statement multiple times — each time with a different bind variable. The BIND_ARRAY procedure lets you bind a collection of scalars, each value of which is used as an input variable once for each EXECUTE. This is similar to the array interface supported by the OCI.

DEFINE_COLUMN, DEFINE_COLUMN_LONG, or DEFINE_ARRAY

The columns of the row being selected in a SELECT statement are identified by their relative positions as they appear in the select list, from left to right. For a query, you must call one of the define procedures (DEFINE_COLUMN, DEFINE_COLUMN_LONG, or DEFINE_ARRAY) to specify the variables that are to receive the SELECT values, much the way an INTO clause does for a static query.

Use the DEFINE_COLUMN_LONG procedure to define LONG columns, in the same way that DEFINE_COLUMN is used to define non-LONG columns. You must call DEFINE_COLUMN_LONG before using the COLUMN_VALUE_LONG procedure to fetch from the LONG column.

Use the DEFINE_ARRAY procedure to define a PL/SQL collection into which you want to fetch rows in a single SELECT statement. DEFINE_ARRAY provides an interface to fetch multiple rows at one fetch. You must call DEFINE_ARRAY before using the COLUMN_VALUE procedure to fetch the rows.

EXECUTE

Call the EXECUTE function to run your SQL statement.

FETCH_ROWS or EXECUTE_AND_FETCH

The FETCH_ROWS function retrieves the rows that satisfy the query. Each successive fetch retrieves another set of rows, until the fetch is unable to retrieve anymore rows. Instead of calling EXECUTE and then FETCH_ROWS, you may find it more efficient to call EXECUTE_AND_FETCH if you are calling EXECUTE for a single execution.

VARIABLE_VALUE, COLUMN_VALUE, or COLUMN_VALUE_LONG

For queries, call COLUMN_VALUE to determine the value of a column retrieved by the FETCH_ROWS call. For anonymous blocks containing calls to PL/SQL procedures or DML statements with returning clause, call VARIABLE_VALUE to retrieve the values assigned to the output variables when statements were run.

To fetch just part of a LONG database column (which can be up to two gigabytes in size), use the COLUMN_VALUE_LONG procedure. You can specify the offset (in bytes) into the column value, and the number of bytes to fetch.

CLOSE_CURSOR

When you no longer need a cursor for a session, close the cursor by calling CLOSE_CURSOR. If you are using an Oracle Open Gateway, then you may need to close cursors at other times as well. Consult your Oracle Open Gateway documentation for additional information.

If you neglect to close a cursor, then the memory used by that cursor remains allocated even though it is no longer needed.

Processing Queries

If you are using dynamic SQL to process a query, then you must perform the following steps:

1. Specify the variables that are to receive the values returned by the SELECT statement by calling the DEFINE_COLUMN Procedures, the DEFINE_COLUMN_LONG Procedure, or the DEFINE_ARRAY Procedure.

2. Run your SELECT statement by calling the EXECUTE Function.

3. Call the FETCH_ROWS Function (or EXECUTE_AND_FETCH) to retrieve the rows that satisfied your query.

4. Call COLUMN_VALUE Procedure or COLUMN_VALUE_LONG Procedure to determine the value of a column retrieved by the FETCH_ROWS Function for your query. If you used anonymous blocks containing calls to PL/SQL procedures, then you must call the VARIABLE_VALUE Procedures to retrieve the values assigned to the output variables of these procedures.

Processing Updates, Inserts, and Deletes

If you are using dynamic SQL to process an INSERT, UPDATE, or DELETE, then you must perform the following steps:

1. You must first run your INSERT, UPDATE, or DELETE statement by calling the EXECUTE Function.

2. If statements have the returning clause, then you must call the VARIABLE_VALUE Procedures to retrieve the values assigned to the output variables.

Locating Errors

There are additional functions in the DBMS_SQL package for obtaining information about the last referenced cursor in the session. The values returned by these functions are only meaningful immediately after a SQL statement is run. In addition, some error-locating functions are only meaningful after certain DBMS_SQL calls. For example, you call the LAST_ERROR_POSITION Function immediately after a PARSE.

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Examples

This section provides example procedures that make use of the DBMS_SQL package.

Example 1

This example does not require the use of dynamic SQL because the text of the statement is known at compile time, but it illustrate the basic concept underlying the package.

The DEMO procedure deletes all of the employees from the EMP table whose salaries are greater than the salary that you specify when you run DEMO.

CREATE OR REPLACE PROCEDURE demo(salary IN NUMBER) AS
    cursor_name INTEGER;
    rows_processed INTEGER;
BEGIN
    cursor_name := dbms_sql.open_cursor;
    DBMS_SQL.PARSE(cursor_name, 'DELETE FROM emp WHERE sal > :x',
                   DBMS_SQL.NATIVE);
    DBMS_SQL.BIND_VARIABLE(cursor_name, ':x', salary);
    rows_processed := DBMS_SQL.EXECUTE(cursor_name);
    DBMS_SQL.CLOSE_CURSOR(cursor_name);
EXCEPTION
WHEN OTHERS THEN
    DBMS_SQL.CLOSE_CURSOR(cursor_name);
END;

Example 2

The following sample procedure is passed a SQL statement, which it then parses and runs:

CREATE OR REPLACE PROCEDURE exec(STRING IN varchar2) AS
    cursor_name INTEGER;
    ret INTEGER;
BEGIN
   cursor_name := DBMS_SQL.OPEN_CURSOR;
  

DDL statements are run by the parse call, which performs the implied commit.

DBMS_SQL.PARSE(cursor_name, string, DBMS_SQL.NATIVE);
   ret := DBMS_SQL.EXECUTE(cursor_name);
   DBMS_SQL.CLOSE_CURSOR(cursor_name);
END;

Creating such a procedure enables you to perform the following operations:

• The SQL statement can be dynamically generated at runtime by the calling program.

• The SQL statement can be a DDL statement or a DML without binds.

For example, after creating this procedure, you could make the following call:

exec('create table acct(c1 integer)');

You could even call this procedure remotely, as shown in the following example. This lets you perform remote DDL.

exec@hq.com('CREATE TABLE acct(c1 INTEGER)');

Example 3

The following sample procedure is passed the names of a source and a destination table, and copies the rows from the source table to the destination table. This sample procedure assumes that both the source and destination tables have the following columns:

id        of type NUMBER
name      of type VARCHAR2(30)
birthdate of type DATE

This procedure does not specifically require the use of dynamic SQL; however, it illustrates the concepts of this package.

CREATE OR REPLACE PROCEDURE copy ( 
     source      IN VARCHAR2, 
     destination IN VARCHAR2) IS 
     id_var             NUMBER; 
     name_var           VARCHAR2(30); 
     birthdate_var      DATE; 
     source_cursor      INTEGER; 
     destination_cursor INTEGER; 
     ignore             INTEGER; 
  BEGIN 
 
  -- Prepare a cursor to select from the source table: 
     source_cursor := dbms_sql.open_cursor; 
     DBMS_SQL.PARSE(source_cursor, 
         'SELECT id, name, birthdate FROM ' || source, 
          DBMS_SQL.NATIVE); 
     DBMS_SQL.DEFINE_COLUMN(source_cursor, 1, id_var); 
     DBMS_SQL.DEFINE_COLUMN(source_cursor, 2, name_var, 30); 
     DBMS_SQL.DEFINE_COLUMN(source_cursor, 3, birthdate_var); 
     ignore := DBMS_SQL.EXECUTE(source_cursor); 
 
  -- Prepare a cursor to insert into the destination table: 
     destination_cursor := DBMS_SQL.OPEN_CURSOR; 
     DBMS_SQL.PARSE(destination_cursor, 
                  'INSERT INTO ' || destination || 
                  ' VALUES (:id_bind, :name_bind, :birthdate_bind)', 
                   DBMS_SQL.NATIVE); 
 
  -- Fetch a row from the source table and insert it into the destination table: 
     LOOP 
       IF DBMS_SQL.FETCH_ROWS(source_cursor)>0 THEN 
         -- get column values of the row 
         DBMS_SQL.COLUMN_VALUE(source_cursor, 1, id_var); 
         DBMS_SQL.COLUMN_VALUE(source_cursor, 2, name_var); 
         DBMS_SQL.COLUMN_VALUE(source_cursor, 3, birthdate_var); 
 
  -- Bind the row into the cursor that inserts into the destination table. You 
  -- could alter this example to require the use of dynamic SQL by inserting an 
  -- if condition before the bind. 
        DBMS_SQL.BIND_VARIABLE(destination_cursor, ':id_bind', id_var); 
        DBMS_SQL.BIND_VARIABLE(destination_cursor, ':name_bind', name_var); 
        DBMS_SQL.BIND_VARIABLE(destination_cursor, ':birthdate_bind', 
birthdate_var); 
        ignore := DBMS_SQL.EXECUTE(destination_cursor); 
      ELSE 
 
  -- No more rows to copy: 
        EXIT; 
      END IF; 
    END LOOP; 
 
  -- Commit and close all cursors: 
     COMMIT; 
     DBMS_SQL.CLOSE_CURSOR(source_cursor); 
     DBMS_SQL.CLOSE_CURSOR(destination_cursor); 
   EXCEPTION 
     WHEN OTHERS THEN 
       IF DBMS_SQL.IS_OPEN(source_cursor) THEN 
         DBMS_SQL.CLOSE_CURSOR(source_cursor); 
       END IF; 
       IF DBMS_SQL.IS_OPEN(destination_cursor) THEN 
         DBMS_SQL.CLOSE_CURSOR(destination_cursor); 
       END IF; 
       RAISE; 
  END; 
/ 

Examples 3, 4, and 5: Bulk DML

This series of examples shows how to use bulk array binds (table items) in the SQL DML statements INSERT, UPDATE and DELETE.

Here is an example of a bulk INSERT statement that demonstrates adding seven new employees to the emp table:

DECLARE
  stmt VARCHAR2(200);
  empno_array      DBMS_SQL.NUMBER_TABLE;
  empname_array    DBMS_SQL.VARCHAR2_TABLE;
  jobs_array       DBMS_SQL.VARCHAR2_TABLE;
  mgr_array        DBMS_SQL.NUMBER_TABLE;
  hiredate_array   DBMS_SQL.VARCHAR2_TABLE;
  sal_array        DBMS_SQL.NUMBER_TABLE;
  comm_array       DBMS_SQL.NUMBER_TABLE;
  deptno_array     DBMS_SQL.NUMBER_TABLE;
  c                NUMBER;
  dummy            NUMBER;
BEGIN
  empno_array(1):= 9001;
  empno_array(2):= 9002;
  empno_array(3):= 9003;
  empno_array(4):= 9004;
  empno_array(5):= 9005;
  empno_array(6):= 9006;
  empno_array(7):= 9007;

  empname_array(1) := 'Dopey';
  empname_array(2) := 'Grumpy';
  empname_array(3) := 'Doc';
  empname_array(4) := 'Happy';
  empname_array(5) := 'Bashful';
  empname_array(6) := 'Sneezy';
  empname_array(7) := 'Sleepy';

  jobs_array(1) := 'Miner';
  jobs_array(2) := 'Miner';
  jobs_array(3) := 'Miner';
  jobs_array(4) := 'Miner';
  jobs_array(5) := 'Miner';
  jobs_array(6) := 'Miner';
  jobs_array(7) := 'Miner';

  mgr_array(1) := 9003;
  mgr_array(2) := 9003;
  mgr_array(3) := 9003;
  mgr_array(4) := 9003;
  mgr_array(5) := 9003;
  mgr_array(6) := 9003;
  mgr_array(7) := 9003;

  hiredate_array(1) := '06-DEC-2006';
  hiredate_array(2) := '06-DEC-2006';
  hiredate_array(3) := '06-DEC-2006';
  hiredate_array(4) := '06-DEC-2006';
  hiredate_array(5) := '06-DEC-2006';
  hiredate_array(6) := '06-DEC-2006';
  hiredate_array(7) := '06-DEC-2006';

  sal_array(1):= 1000;
  sal_array(2):= 1000;
  sal_array(3):= 1000;
  sal_array(4):= 1000;
  sal_array(5):= 1000;
  sal_array(6):= 1000;
  sal_array(7):= 1000;

  comm_array(1):= 0;
  comm_array(2):= 0;
  comm_array(3):= 0;
  comm_array(4):= 0;
  comm_array(5):= 0;
  comm_array(6):= 0;
  comm_array(7):= 0;

  deptno_array(1):= 11;
  deptno_array(2):= 11;
  deptno_array(3):= 11;
  deptno_array(4):= 11;
  deptno_array(5):= 11;
  deptno_array(6):= 11;
  deptno_array(7):= 11;

  stmt := 'INSERT INTO emp VALUES(
     :num_array, :name_array, :jobs_array, :mgr_array, :hiredate_array, 
     :sal_array, :comm_array, :deptno_array)';
  c := DBMS_SQL.OPEN_CURSOR;
  DBMS_SQL.PARSE(c, stmt, DBMS_SQL.NATIVE);
  DBMS_SQL.BIND_ARRAY(c, ':num_array', empno_array);
  DBMS_SQL.BIND_ARRAY(c, ':name_array', empname_array);
  DBMS_SQL.BIND_ARRAY(c, ':jobs_array', jobs_array);
  DBMS_SQL.BIND_ARRAY(c, ':mgr_array', mgr_array);
  DBMS_SQL.BIND_ARRAY(c, ':hiredate_array', hiredate_array);
  DBMS_SQL.BIND_ARRAY(c, ':sal_array', sal_array);
  DBMS_SQL.BIND_ARRAY(c, ':comm_array', comm_array);
  DBMS_SQL.BIND_ARRAY(c, ':deptno_array', deptno_array);

  dummy := DBMS_SQL.EXECUTE(c);
  DBMS_SQL.CLOSE_CURSOR(c);
  EXCEPTION WHEN OTHERS THEN
    IF DBMS_SQL.IS_OPEN(c) THEN
      DBMS_SQL.CLOSE_CURSOR(c);
    END IF;
    RAISE;
END;
/
SHOW ERRORS;

Here is an example of a bulk UPDATE statement that demonstrates updating salaries for four existing employees in the emp table:

DECLARE
  stmt VARCHAR2(200);
  empno_array     DBMS_SQL.NUMBER_TABLE;
  salary_array    DBMS_SQL.NUMBER_TABLE;
  c               NUMBER;
  dummy           NUMBER;
BEGIN
 
  empno_array(1):= 7369;
  empno_array(2):= 7876;
  empno_array(3):= 7900;
  empno_array(4):= 7934;
 
  salary_array(1) := 10000;
  salary_array(2) := 10000;
  salary_array(3) := 10000;
  salary_array(4) := 10000;
 
  stmt := 'update emp set sal = :salary_array
    WHERE empno = :num_array';
  c := DBMS_SQL.OPEN_CURSOR;
  DBMS_SQL.PARSE(c, stmt, DBMS_SQL.NATIVE);
  DBMS_SQL.BIND_ARRAY(c, ':num_array', empno_array);
  DBMS_SQL.BIND_ARRAY(c, ':salary_array', salary_array);
  dummy := DBMS_SQL.EXECUTE(c);
  DBMS_SQL.CLOSE_CURSOR(c);
 
  EXCEPTION WHEN OTHERS THEN
    IF DBMS_SQL.IS_OPEN(c) THEN
      DBMS_SQL.CLOSE_CURSOR(c);
    END IF;
    RAISE;
END;
/

In a DELETE statement, for example, you could bind in an array in the WHERE clause and have the statement be run for each element in the array:

DECLARE
  stmt VARCHAR2(200);
  dept_no_array DBMS_SQL.NUMBER_TABLE;
  c NUMBER;
  dummy NUMBER;
begin
  dept_no_array(1) := 10; dept_no_array(2) := 20;
  dept_no_array(3) := 30; dept_no_array(4) := 40;
  dept_no_array(5) := 30; dept_no_array(6) := 40;
  stmt := 'delete from emp where deptno = :dept_array';
  c := DBMS_SQL.OPEN_CURSOR;
  DBMS_SQL.PARSE(c, stmt, DBMS_SQL.NATIVE);
  DBMS_SQL.BIND_ARRAY(c, ':dept_array', dept_no_array, 1, 4);
  dummy := DBMS_SQL.EXECUTE(c);
  DBMS_SQL.CLOSE_CURSOR(c); 

  EXCEPTION WHEN OTHERS THEN
    IF DBMS_SQL.IS_OPEN(c) THEN
      DBMS_SQL.CLOSE_CURSOR(c);
    END IF;
    RAISE;
END;
/ 

In the preceding example, only elements 1 through 4 are used as specified by the BIND_ARRAY call. Each element of the array potentially deletes a large number of employees from the database.

Examples 6 and 7: Defining an Array

The following examples show how to use the DEFINE_ARRAY procedure:

declare
  c       NUMBER;
  d       NUMBER;
  n_tab   DBMS_SQL.NUMBER_TABLE;
  indx    NUMBER := -10;
BEGIN
  c := DBMS_SQL.OPEN_CURSOR;
  dBMS_SQL.PARSE(c, 'select n from t order by 1', DBMS_SQL.NATIVE);

  DBMS_SQL.DEFINE_ARRAY(c, 1, n_tab, 10, indx);

  d := DBMS_SQL.EXECUTE(c);
  loop
    d := DBMS_SQL.FETCH_ROWS(c);

    DBMS_SQL.COLUMN_VALUE(c, 1, n_tab);

    EXIT WHEN d != 10;
  END LOOP;

  DBMS_SQL.CLOSE_CURSOR(c);

  EXCEPTION WHEN OTHERS THEN
    IF DBMS_SQL.IS_OPEN(c) THEN
      DBMS_SQL.CLOSE_CURSOR(c);
    END IF;
    RAISE;
END;
/

Each time the preceding example does a FETCH_ROWS Function call, it fetches 10 rows that are kept in DBMS_SQL buffers. When the COLUMN_VALUE Procedure call is run, those rows move into the PL/SQL table specified (in this case n_tab), at positions -10 to -1, as specified in the DEFINE statements. When the second batch is fetched in the loop, the rows go to positions 0 to 9; and so on.

A current index into each array is maintained automatically. This index is initialized to "indx" at EXECUTE and keeps getting updated every time a COLUMN_VALUE call is made. If you re-execute at any point, then the current index for each DEFINE is re-initialized to "indx".

In this way the entire result of the query is fetched into the table. When FETCH_ROWS cannot fetch 10 rows, it returns the number of rows actually fetched (if no rows could be fetched, then it returns zero) and exits the loop.

Here is another example of using the DEFINE_ARRAY procedure:

Consider a table MULTI_TAB defined as:

CREATE TABLE multi_tab (num NUMBER, 
                        dat1 DATE, 
                        var VARCHAR2(24), 
                        dat2 DATE) 

To select everything from this table and move it into four PL/SQL tables, you could use the following simple program:

declare
  c       NUMBER;
  d       NUMBER;
  n_tab  DBMS_SQL.NUMBER_TABLE;
  d_tab1 DBMS_SQL.DATE_TABLE;
  v_tab  DBMS_SQL.VARCHAR2_TABLE;
  d_tab2 DBMS_SQL.DATE_TABLE;
  indx NUMBER := 10;
BEGIN

  c := DBMS_SQL.OPEN_CURSOR;
  DBMS_SQL.PARSE(c, 'select * from multi_tab order by 1', DBMS_SQL.NATIVE);

  DBMS_SQL.DEFINE_ARRAY(c, 1, n_tab,  5, indx);
  DBMS_SQL.DEFINE_ARRAY(c, 2, d_tab1, 5, indx);
  DBMS_SQL.DEFINE_ARRAY(c, 3, v_tab,  5, indx);
  DBMS_SQL.DEFINE_ARRAY(c, 4, d_tab2, 5, indx);

  d := DBMS_SQL.EXECUTE(c);

  loop
    d := DBMS_SQL.FETCH_ROWS(c);

    DBMS_SQL.COLUMN_VALUE(c, 1, n_tab);
    DBMS_SQL.COLUMN_VALUE(c, 2, d_tab1);
    DBMS_SQL.COLUMN_VALUE(c, 3, v_tab);
    DBMS_SQL.COLUMN_VALUE(c, 4, d_tab2);
  
    EXIT WHEN d != 5;
  END LOOP;

  DBMS_SQL.CLOSE_CURSOR(c);

/* 

The four tables can be used for anything. One usage might be to use BIND_ARRAY to move the rows to another table by using a statement such as 'INSERT into SOME_T values (:a, :b, :c, :d);

*/

EXCEPTION WHEN OTHERS THEN
    IF DBMS_SQL.IS_OPEN(c) THEN
      DBMS_SQL.CLOSE_CURSOR(c);
    END IF;
    RAISE;
END;
/

Example 8: Describe Columns

This can be used as a substitute to the SQL*Plus DESCRIBE call by using a SELECT * query on the table that you want to describe.

DECLARE
  c           NUMBER;
  d           NUMBER;
  col_cnt     INTEGER;
  f           BOOLEAN;
  rec_tab     DBMS_SQL.DESC_TAB;
  col_num    NUMBER;
  PROCEDURE print_rec(rec in DBMS_SQL.DESC_REC) IS
  BEGIN
    DBMS_OUTPUT.NEW_LINE;
    DBMS_OUTPUT.PUT_LINE('col_type            =    '
                         || rec.col_type);
    DBMS_OUTPUT.PUT_LINE('col_maxlen          =    '
                         || rec.col_max_len);
    DBMS_OUTPUT.PUT_LINE('col_name            =    '
                         || rec.col_name);
    DBMS_OUTPUT.PUT_LINE('col_name_len        =    '
                         || rec.col_name_len);
    DBMS_OUTPUT.PUT_LINE('col_schema_name     =    '
                         || rec.col_schema_name);
    DBMS_OUTPUT.PUT_LINE('col_schema_name_len =    '
                         || rec.col_schema_name_len);
    DBMS_OUTPUT.PUT_LINE('col_precision       =    '
                         || rec.col_precision);
    DBMS_OUTPUT.PUT_LINE('col_scale           =    '
                         || rec.col_scale);
    DBMS_OUTPUT.PUT('col_null_ok         =    ');
    IF (rec.col_null_ok) THEN
      DBMS_OUTPUT.PUT_LINE('true');
    ELSE
      DBMS_OUTPUT.PUT_LINE('false');
    END IF;
  END;
BEGIN
  c := DBMS_SQL.OPEN_CURSOR;

  DBMS_SQL.PARSE(c, 'SELECT * FROM scott.bonus', DBMS_SQL.NATIVE);
 
  d := DBMS_SQL.EXECUTE(c);
 
  DBMS_SQL.DESCRIBE_COLUMNS(c, col_cnt, rec_tab);

/*
 * Following loop could simply be for j in 1..col_cnt loop.
 * Here we are simply illustrating some of the PL/SQL table
 * features.
 */
  col_num := rec_tab.first;
  IF (col_num IS NOT NULL) THEN
    LOOP
      print_rec(rec_tab(col_num));
      col_num := rec_tab.next(col_num);
      EXIT WHEN (col_num IS NULL);
    END LOOP;
  END IF;
 
  DBMS_SQL.CLOSE_CURSOR(c);
END;
/

Example 9: RETURNING clause

The RETURNING clause was added to DML statements in an earlier Oracle database release. With this clause, INSERT, UPDATE, and DELETE statements can return values of expressions. These values are returned in bind variables.

DBMS_SQL.BIND_VARIABLE is used to bind these outbinds if a single row is inserted, updated, or deleted. If multiple rows are inserted, updated, or deleted, then DBMS_SQL.BIND_ARRAY is used. DBMS_SQL.VARIABLE_VALUE must be called to get the values in these bind variables.

i) Single row insert

CREATE OR REPLACE PROCEDURE single_Row_insert
           (c1 NUMBER, c2 NUMBER, r OUT NUMBER) is
      c NUMBER;
      n NUMBER;
      begin
        c := DBMS_SQL.OPEN_CURSOR;
        DBMS_SQL.PARSE(c, 'INSERT INTO tab VALUES (:bnd1, :bnd2) ' ||
                          'RETURNING c1*c2 INTO :bnd3', DBMS_SQL.NATIVE);
     DBMS_SQL.BIND_VARIABLE(c, 'bnd1', c1);
        DBMS_SQL.BIND_VARIABLE(c, 'bnd2', c2);
        DBMS_SQL.BIND_VARIABLE(c, 'bnd3', r);
        n := DBMS_SQL.EXECUTE(c); 
        DBMS_SQL.VARIABLE_VALUE(c, 'bnd3', r); -- get value of outbind variable
        DBMS_SQL.CLOSE_CURSOR(c);
      END;
      /
 

ii) Single row update

CREATE OR REPLACE PROCEDURE single_Row_update
           (c1 NUMBER, c2 NUMBER, r out NUMBER) IS
      c NUMBER;
      n NUMBER;
      BEGIN
        c := DBMS_SQL.OPEN_CURSOR;
        DBMS_SQL.PARSE(c, 'UPDATE tab SET c1 = :bnd1, c2 = :bnd2 ' ||
                          'WHERE rownum < 2' || 
                          'RETURNING c1*c2 INTO :bnd3', DBMS_SQL.NATIVE);
        DBMS_SQL.BIND_VARIABLE(c, 'bnd1', c1);
        DBMS_SQL.BIND_VARIABLE(c, 'bnd2', c2);
        DBMS_SQL.BIND_VARIABLE(c, 'bnd3', r);
        n := DBMS_SQL.EXECUTE(c); 
        DBMS_SQL.VARIABLE_VALUE(c, 'bnd3', r);-- get value of outbind variable
        DBMS_SQL.CLOSE_CURSOR(c);
      END;
      /

iii) Single row delete

CREATE OR REPLACE PROCEDURE single_Row_Delete
           (c1 NUMBER, c2 NUMBER, r OUT NUMBER) is
      c NUMBER;
      n number;
      BEGIN
        c := DBMS_SQL.OPEN_CURSOR;
        DBMS_SQL.PARSE(c, 'delete from tab ' ||
                          'where rownum < 2 ' ||
                         'returning c1*c2 into :bnd3', DBMS_SQL.NATIVE);
        DBMS_SQL.BIND_VARIABLE(c, 'bnd1', c1);
        DBMS_SQL.BIND_VARIABLE(c, 'bnd2', c2);
        DBMS_SQL.BIND_VARIABLE(c, 'bnd3', r);
        n := DBMS_SQL.EXECUTE(c); 
        DBMS_SQL.VARIABLE_VALUE(c, 'bnd3', r);-- get value of outbind variable
        DBMS_SQL.CLOSE_CURSOR(c);
      END;
      /
 

iv) Multiple row insert

CREATE OR REPLACE PROCEDURE multi_Row_insert
           (c1 DBMS_SQL.NUMBER_TABLE, c2 DBMS_SQL.NUMBER_TABLE, 
            r OUT DBMS_SQL.NUMBER_TABLE) is
      c NUMBER;
      n NUMBER;
      BEGIN
        c := DBMS_SQL.OPEN_CURSOR;
        DBMS_SQL.PARSE(c, 'insert into tab VALUES (:bnd1, :bnd2) ' ||
                          'RETURNING c1*c2 INTO :bnd3', DBMS_SQL.NATIVE);
        DBMS_SQL.BIND_ARRAY(c, 'bnd1', c1);
        DBMS_SQL.BIND_ARRAY(c, 'bnd2', c2);
        DBMS_SQL.BIND_ARRAY(c, 'bnd3', r);
        n := DBMS_SQL.EXECUTE(c); 
        DBMS_SQL.VARIABLE_VALUE(c, 'bnd3', r);-- get value of outbind variable
        DBMS_SQL.CLOSE_CURSOR(c);
      END;
      /

v) Multiple row Update.

CREATE OR REPLACE PROCEDURE multi_Row_update
           (c1 NUMBER, c2 NUMBER, r OUT DBMS_SQL.NUMBER_TABLE) IS
      c NUMBER;
      n NUMBER;
     BEGIN
        c := DBMS_SQL.OPEN_CURSOR;
        DBMS_SQL.PARSE(c, 'UPDATE tab SET c1 = :bnd1 WHERE c2 = :bnd2 ' ||
                          'RETURNING c1*c2 INTO :bnd3', DBMS_SQL.NATIVE);
        DBMS_SQL.BIND_VARIABLE(c, 'bnd1', c1);
        DBMS_SQL.BIND_VARIABLE(c, 'bnd2', c2);
        DBMS_SQL.BIND_ARRAY(c, 'bnd3', r);
        n := DBMS_SQL.EXECUTE(c); 
        DBMS_SQL.VARIABLE_VALUE(c, 'bnd3', r);-- get value of outbind variable
        DBMS_SQL.CLOSE_CURSOR(c);
      END;
      /

vi) Multiple row delete

CREATE OR REPLACE PROCEDURE multi_row_delete
           (c1 DBMS_SQL.NUMBER_TABLE,
            r OUT DBMS_SQL.NUMBER_TABLE) is
      c NUMBER;
      n NUMBER;
      BEGIN
        c := DBMS_SQL.OPEN_CURSOR;
        DBMS_SQL.PARSE(c, 'DELETE FROM tab WHERE c1 = :bnd1' ||
                          'RETURNING c1*c2 INTO :bnd2', DBMS_SQL.NATIVE);
        DBMS_SQL.BIND_ARRAY(c, 'bnd1', c1);
        DBMS_SQL.BIND_ARRAY(c, 'bnd2', r);
        n := DBMS_SQL.EXECUTE(c); 
        DBMS_SQL.VARIABLE_VALUE(c, 'bnd2', r);-- get value of outbind variable
        DBMS_SQL.CLOSE_CURSOR(c);
      END;
      /

vii) Out-bind in bulk PL/SQL

CREATE OR REPLACE PROCEDURE foo (n NUMBER, square OUT NUMBER) IS
      BEGIN square := n * n; END;/
 
      CREATE OR REPLACE PROCEDURE bulk_plsql 
         (n DBMS_SQL.NUMBER_TABLE, square OUT DBMS_SQL.NUMBER_TABLE) IS
      c NUMBER;
      r NUMBER;
      BEGIN
        c := DBMS_SQL.OPEN_CURSOR;
        DBMS_SQL.PARSE(c, 'BEGIN foo(:bnd1, :bnd2); END;', DBMS_SQL.NATIVE);
        DBMS_SQL.BIND_ARRAY(c, 'bnd1', n);
        DBMS_SQL.BIND_ARRAY(c, 'bnd2', square);
        r := DBMS_SQL.EXECUTE(c);
        DBMS_SQL.VARIABLE_VALUE(c, 'bnd2', square);
     END;
     /

Example 10: Binds and Defines of User-defined Types in DBMS_SQL

CREATE TYPE dnames_var IS VARRAY(7) OF VARCHAR2(30)
/
 
CREATE TABLE depts (region VARCHAR2(25), dept_names dnames_var)
/
 
INSERT INTO depts VALUES('Europe', dnames_var('Shipping','Sales','Finance'))
/
INSERT INTO depts VALUES('Americas', dnames_var('Sales','Finance','Shipping'))
/
INSERT INTO depts 
     VALUES('Asia', dnames_var('Finance','Payroll','Shipping','Sales'))
/
 
CREATE OR REPLACE PROCEDURE update_depts(new_dnames dnames_var, region VARCHAR2) IS
   some_dnames dnames_var;
   c      NUMBER;
   r      NUMBER;
   sql_stmt VARCHAR2(32767) :=
    'UPDATE depts SET dept_names = :b1 WHERE region = :b2 RETURNING dept_names INTO :b3';
 
BEGIN
 
   c := DBMS_SQL.OPEN_CURSOR;
 
   DBMS_SQL.PARSE(c, sql_stmt, dbms_sql.native);
 
   DBMS_SQL.BIND_VARIABLE(c, 'b1', new_dnames);
   DBMS_SQL.BIND_VARIABLE(c, 'b2', region);
   DBMS_SQL.BIND_VARIABLE(c, 'b3', some_dnames);
 
   r := DBMS_SQL.EXECUTE(c);
 
   -- Get value of outbind variable
   DBMS_SQL.VARIABLE_VALUE(c, 'b3', some_dnames);
 
   DBMS_SQL.CLOSE_CURSOR(c);
 
   -- select dept_names
   sql_stmt := 'SELECT dept_names FROM depts WHERE region = :b1';
 
   c := DBMS_SQL.OPEN_CURSOR;
   DBMS_SQL.PARSE(c, sql_stmt, dbms_sql.native);
 
   DBMS_SQL.DEFINE_COLUMN(c, 1, some_dnames);
   DBMS_SQL.BIND_VARIABLE(c, 'b1', region);
 
   r := DBMS_SQL.EXECUTE_AND_FETCH(c);
 
   DBMS_SQL.COLUMN_VALUE(c, 1, some_dnames);
 
   DBMS_SQL.CLOSE_CURSOR(c);
 
    -- loop through some_dnames collections
    FOR i IN some_dnames.FIRST .. some_dnames.LAST  LOOP
        DBMS_OUTPUT.PUT_LINE('Dept. Name = ' || some_dnames(i) || ' Updated!');
    END LOOP;
END;
/
 
DECLARE
  new_dnames dnames_var;
BEGIN
  new_dnames := dnames_var('Benefits', 'Advertising', 'Contracting', 
                           'Executive', 'Marketing');
  update_depts(new_dnames, 'Asia');
END;
/

Data Structures

The DBMS_SQL package defines the following RECORD types and TABLE types.

RECORD Types

• DESC_REC Record Type

• DESC_REC2 Record Type

• DESC_REC3 Record Type

TABLE Types

• BFILE_TABLE Table Type

• BINARY_DOUBLE_TABLE Table Type

• BINARY_FLOAT_TABLE Table Type

• BLOB_TABLE Table Type

• CLOB_TABLE Table Type

• DATE_TABLE Table Type

• DESC_TAB Table Type

• DESC_TAB2 Table Type

• DESC_TAB3 Table Type

• INTERVAL_DAY_TO_SECOND_TABLE Table Type

• INTERVAL_YEAR_TO_MONTH_TABLE Table Type

• NUMBER_TABLE Table Type

• TIME_TABLE Table Type

• TIME_WITH_TIME_ZONE_TABLE Table Type

• TIMESTAMP_TABLE Table Type

• TIMESTAMP_WITH_LTZ_TABLE Table Type

• TIMESTAMP_WITH_TIME_ZONE_TABLE Table Type

• UROWID_TABLE Table Type

• VARCHAR2_TABLE Table Type

• VARCHAR2A Table Type

• VARCHAR2S Table Type

---

DESC_REC Record Type

This record type holds the describe information for a single column in a dynamic query. It is the element type of the DESC_TAB table type and the DESCRIBE_COLUMNS Procedure.

Syntax

TYPE desc_rec IS RECORD (
      col_type            BINARY_INTEGER := 0,
      col_max_len         BINARY_INTEGER := 0,
      col_name            VARCHAR2(32)   := '',
      col_name_len        BINARY_INTEGER := 0,
      col_schema_name     VARCHAR2(32)   := '',
      col_schema_name_len BINARY_INTEGER := 0,
      col_precision       BINARY_INTEGER := 0,
      col_scale           BINARY_INTEGER := 0,
      col_charsetid       BINARY_INTEGER := 0,
      col_charsetform     BINARY_INTEGER := 0,
      col_null_ok         BOOLEAN        := TRUE);
TYPE desc_tab IS TABLE OF desc_rec INDEX BY BINARY_INTEGER;

Fields

---

DESC_REC2 Record Type

DESC_REC2 is the element type of the DESC_TAB2 table type and the DESCRIBE_COLUMNS2 Procedure.

This record type is identical to DESC_REC except for the col_name field, which has been expanded to the maximum possible size for VARCHAR2. It is therefore preferred to DESC_REC because column name values can be greater than 32 characters. DESC_REC is deprecated as a result.

Syntax

TYPE desc_rec2 IS RECORD (
   col_type            binary_integer := 0,
   col_max_len         binary_integer := 0,
   col_name            varchar2(32767) := '',
   col_name_len        binary_integer := 0,
   col_schema_name     varchar2(32)   := '',
   col_schema_name_len binary_integer := 0,
   col_precision       binary_integer := 0,
   col_scale           binary_integer := 0,
   col_charsetid       binary_integer := 0,
   col_charsetform     binary_integer := 0,
   col_null_ok         boolean        := TRUE);

Fields

---

DESC_REC3 Record Type

DESC_REC3 is the element type of the DESC_TAB3 table type and the DESCRIBE_COLUMNS3 Procedure.

DESC_REC3 is identical to DESC_REC2 except for two additional fields to hold the type name (type_name) and type name len (type_name_len) of a column in a dynamic query. These two fields hold the type name and type name length when the column is a user-defined type (a collection or object type). The col_type_name and col_type_name_len fields are only populated when the col_type field's value is 109, the Oracle type number for user-defined types.

Syntax

TYPE desc_rec3 IS RECORD (
   col_type               binary_integer := 0,
   col_max_len            binary_integer := 0,
   col_name               varchar2(32767) := '',
   col_name_len           binary_integer := 0,
   col_schema_name        varchar2(32) := '',
   col_schema_name_len    binary_integer := 0,
   col_precision          binary_integer := 0,
   col_scale              binary_integer := 0,
   col_charsetid          binary_integer := 0,
   col_charsetform        binary_integer := 0,
   col_null_ok            boolean := TRUE,
   col_type_name          varchar2(32767)   := '',
   col_type_name_len      binary_integer := 0);

Fields

---

BFILE_TABLE Table Type

This is a table of BFILE.

Syntax

TYPE bfile_table IS TABLE OF BFILE INDEX BY BINARY_INTEGER;

---

BINARY_DOUBLE_TABLE Table Type

This is a table of BINARY_DOUBLE.

Syntax

TYPE binary_double_table IS TABLE OF BINARY_DOUBLE INDEX BY BINARY_INTEGER;

---

BINARY_FLOAT_TABLE Table Type

This is a table of BINARY_FLOAT.

Syntax

TYPE binary_float_table IS TABLE OF BINARY_FLOAT INDEX BY BINARY_INTEGER;

---

BLOB_TABLE Table Type

This is a table of BLOB.

Syntax

TYPE blob_table IS TABLE OF BLOB INDEX BY BINARY_INTEGER;

---

CLOB_TABLE Table Type

This is a table of CLOB.

Syntax

TYPE clob_table IS TABLE OF CLOB INDEX BY BINARY_INTEGER;

---

DATE_TABLE Table Type

This is a table of DATE.

Syntax

type date_table IS TABLE OF DATE INDEX BY BINARY_INTEGER; 

---

DESC_TAB Table Type

This is a table of DESC_REC Record Type.

Syntax

TYPE desc_tab IS TABLE OF desc_rec INDEX BY BINARY_INTEGER;

---

DESC_TAB2 Table Type

This is a table of DESC_REC2 Record Type.

Syntax

TYPE desc_tab2 IS TABLE OF desc_rec2 INDEX BY BINARY_INTEGER;

---

DESC_TAB3 Table Type

This is a table of DESC_REC3 Record Type.

Syntax

TYPE desc_tab3 IS TABLE OF desc_rec3 INDEX BY BINARY_INTEGER; 

---

INTERVAL_DAY_TO_SECOND_TABLE Table Type

This is a table of DSINTERVAL_UNCONSTRAINED.

Syntax

TYPE interval_day_to_second_Table IS TABLE OF
    DSINTERVAL_UNCONSTRAINED INDEX BY binary_integer;

---

INTERVAL_YEAR_TO_MONTH_TABLE Table Type

This is a table of YMINTERVAL_UNCONSTRAINED.

Syntax

TYPE interval_year_to_month_table IS TABLE OF YMINTERVAL_UNCONSTRAINED 
   INDEX BY BINARY_INTEGER;

---

NUMBER_TABLE Table Type

This is a table of NUMBER.

Syntax

TYPE number_table IS TABLE OF NUMBER INDEX BY BINARY_INTEGER;

---

TIME_TABLE Table Type

This is a table of TIME_UNCONSTRAINED.

Syntax

TYPE time_table IS TABLE OF TIME_UNCONSTRAINED INDEX BY BINARY_INTEGER;

---

TIME_WITH_TIME_ZONE_TABLE Table Type

This is a table of TIME_TZ_UNCONSTRAINED.

Syntax

TYPE time_with_time_zone_table IS TABLE OF TIME_TZ_UNCONSTRAINED 
   INDEX BY BINARY_INTEGER;;

---

TIMESTAMP_TABLE Table Type

This is a table of TIMESTAMP_UNCONSTRAINED.

Syntax

TYPE timestamp_table IS TABLE OF TIMESTAMP_UNCONSTRAINED INDEX BY BINARY_INTEGER;

---

TIMESTAMP_WITH_LTZ_TABLE Table Type

This is a table of TIMESTAMP_LTZ_UNCONSTRAINED

Syntax

TYPE timestamp_with_ltz_table IS TABLE OF
    TIMESTAMP_LTZ_UNCONSTRAINED INDEX BY binary_integer;

---

TIMESTAMP_WITH_TIME_ZONE_TABLE Table Type

This is a table of TIMESTAMP_TZ_UNCONSTRAINED.

Syntax

TYPE timestamp_with_time_zone_Table IS TABLE OF 
    TIMESTAMP_TZ_UNCONSTRAINED INDEX BY binary_integer;

---

UROWID_TABLE Table Type

This is a table of UROWID.

Syntax

TYPE urowid_table IS TABLE OF UROWID INDEX BY BINARY_INTEGER;

---

VARCHAR2_TABLE Table Type

This is table of VARCHAR2(2000).

Syntax

TYPE varchar2_table IS TABLE OF VARCHAR2(2000) INDEX BY BINARY_INTEGER;

---

VARCHAR2A Table Type

This is table of VARCHAR2(32767).

Syntax

TYPE varchar2a IS TABLE OF VARCHAR2(32767) INDEX BY BINARY_INTEGER;

---

VARCHAR2S Table Type

This is table of VARCHAR2(256).

Syntax

TYPE varchar2s IS TABLE OF VARCHAR2(256) INDEX BY BINARY_INTEGER;

Summary of DBMS_SQL Subprograms

---

BIND_ARRAY Procedures

This procedure binds a given value or set of values to a given variable in a cursor, based on the name of the variable in the statement.

Syntax

DBMS_SQL.BIND_ARRAY ( 
   c                   IN INTEGER, 
   name                IN VARCHAR2, 
   <table_variable>    IN <datatype> 
 [,index1              IN INTEGER, 
   index2              IN INTEGER)] ); 

Where the <table_variable> and its corresponding <datatype> can be any one of the following matching pairs:

<clob_tab>     Clob_Table
<bflt_tab>     Binary_Float_Table
<bdbl_tab>     Binary_Double_Table
<blob_tab>     Blob_Table
<bfile_tab>    Bfile_Table
<date_tab>     Date_Table
<num_tab>      Number_Table
<urowid_tab>   Urowid_Table
<vchr2_tab>    Varchar2_Table

Notice that the BIND_ARRAY procedure is overloaded to accept different datatypes.

Parameters

Usage Notes

The length of the bind variable name should be <=30 bytes.

For binding a range, the table must contain the elements that specify the range — tab(index1) and tab(index2) — but the range does not have to be dense. Index1 must be less than or equal to index2. All elements between tab(index1) and tab(index2) are used in the bind.

If you do not specify indexes in the bind call, and two different binds in a statement specify tables that contain a different number of elements, then the number of elements actually used is the minimum number between all tables. This is also the case if you specify indexes — the minimum range is selected between the two indexes for all tables.

Not all bind variables in a query have to be array binds. Some can be regular binds and the same value are used for each element of the collections in expression evaluations (and so forth).

Bulk Array Binds

Bulk selects, inserts, updates, and deletes can enhance the performance of applications by bundling many calls into one. The DBMS_SQL package lets you work on collections of data using the PL/SQL table type.

Table items are unbounded homogeneous collections. In persistent storage, they are like other relational tables and have no intrinsic ordering. But when a table item is brought into the workspace (either by querying or by navigational access of persistent data), or when it is created as the value of a PL/SQL variable or parameter, its elements are given subscripts that can be used with array-style syntax to get and set the values of elements.

The subscripts of these elements need not be dense, and can be any number including negative numbers. For example, a table item can contain elements at locations -10, 2, and 7 only.

When a table item is moved from transient workspace to persistent storage, the subscripts are not stored; the table item is unordered in persistent storage.

At bind time the table is copied out from the PL/SQL buffers into local DBMS_SQL buffers (the same as for all scalar types) and then the table is manipulated from the local DBMS_SQL buffers. Therefore, if you change the table after the bind call, then that change does not affect the way the execute acts.

Types for Scalar and LOB Collections

You can declare a local variable as one of the following table-item types, which are defined as public types in DBMS_SQL.

TYPE binary_double_table 
                    IS TABLE OF BINARY_DOUBLE  INDEX BY BINARY_INTEGER;
TYPE binary_float_table 
                    IS TABLE OF BINARY_FLOAT   INDEX BY BINARY_INTEGER;
TYPE bfile_table    IS TABLE OF BFILE          INDEX BY BINARY_INTEGER;
TYPE blob_table     IS TABLE OF BLOB           INDEX BY BINARY_INTEGER;
TYPE clob_table     IS TABLE OF CLOB           INDEX BY BINARY_INTEGER;
TYPE date_table     IS TABLE OF DATE           INDEX BY BINARY_INTEGER;
TYPE interval_day_to_second_Table 
                    IS TABLE OF dsinterval_unconstrained 
                                               INDEX BY BINARY_INTEGER;
TYPE interval_year_to_MONTH_Table 
                    IS TABLE OF yminterval_unconstrained 
                                               INDEX BY BINARY_INTEGER;
TYPE number_table   IS TABLE OF NUMBER         INDEX BY BINARY_INTEGER;
TYPE time_table     IS TABLE OF time_unconstrained           
                                               INDEX BY BINARY_INTEGER;
TYPE time_with_time_zone_table 
                    IS TABLE OF time_tz_unconstrained 
                                               INDEX BY BINARY_INTEGER;
TYPE timestamp_table 
                    IS TABLE OF timestamp_unconstrained   
                                               INDEX BY BINARY_INTEGER;
TYPE timestamp_with_ltz_Table 
                    IS TABLE OF timestamp_ltz_unconstrained 
                                               INDEX BY BINARY_INTEGER;
TYPE timestamp_with_time_zone_Table 
                    IS TABLE OF timestamp_tz_unconstrained 
                                               INDEX BY BINARY_INTEGER;
TYPE urowid_table   IS TABLE OF UROWID         INDEX BY BINARY_INTEGER;
TYPE varchar2_table IS TABLE OF VARCHAR2(2000) INDEX BY BINARY_INTEGER;

<tm_tab>   Time_Table
<ttz_tab>  Time_With_Time_Zone_Table
<tms_tab>  Timestamp_Table
<tstz_tab> Timestamp_With_ltz_Table;
<tstz_tab> Timestamp_With_Time_Zone_Table
<ids_tab>  Interval_Day_To_Second_Table
<iym_tab>  Interval_Year_To_Month_Table

---

BIND_VARIABLE Procedures

This procedures binds a given value or set of values to a given variable in a cursor, based on the name of the variable in the statement.

Syntax

DBMS_SQL.BIND_VARIABLE (
   c              IN INTEGER,
   name           IN VARCHAR2,
   value          IN <datatype>)

Where <datatype> can be any one of the following types:

BINARY_DOUBLE
BINARY_FLOAT
BFILE
BLOB
CLOB CHARACTER SET ANY_CS
DATE
DSINTERVAL_UNCONSTRAINED
NUMBER
TIME_UNCONSTRAINED
TIME_TZ_UNCONSTRAINED
TIMESTAMP_LTZ_UNCONSTRAINED
TIMESTAMP_TZ_UNCONSTRAINED
TIMESTAMP_UNCONSTRAINED
UROWID
VARCHAR2 CHARACTER SET ANY_CS
YMINTERVAL_UNCONSTRAINED
user-defined object types
collections (VARRAYs and nested tables)
REFs
Opaque types

Notice that BIND_VARIABLE is overloaded to accept different datatypes.

The following syntax is also supported for BIND_VARIABLE. The square brackets [] indicate an optional parameter for the BIND_VARIABLE function.

DBMS_SQL.BIND_VARIABLE (
   c              IN INTEGER,
   name           IN VARCHAR2,
   value          IN VARCHAR2 CHARACTER SET ANY_CS [,out_value_size IN INTEGER]);

To bind CHAR, RAW, and ROWID data, you can use the following variations on the syntax:

DBMS_SQL.BIND_VARIABLE_CHAR (
   c              IN INTEGER,
   name           IN VARCHAR2,
   value          IN CHAR CHARACTER SET ANY_CS [,out_value_size IN INTEGER]);

DBMS_SQL.BIND_VARIABLE_RAW (
   c              IN INTEGER,
   name           IN VARCHAR2,
   value          IN RAW [,out_value_size IN INTEGER]);

DBMS_SQL.BIND_VARIABLE_ROWID (
   c              IN INTEGER,
   name           IN VARCHAR2,
   value          IN ROWID);

Pragmas

pragma restrict_references(bind_variable,WNDS);

Parameters

Usage Notes

If the variable is an IN or IN/OUT variable or an IN collection, then the given bind value must be valid for the variable or array type. Bind values for OUT variables are ignored.

The bind variables or collections of a SQL statement are identified by their names. When binding a value to a bind variable or bind array, the string identifying it in the statement must contain a leading colon, as shown in the following example:

SELECT emp_name FROM emp WHERE SAL > :X;

For this example, the corresponding bind call would look similar to

BIND_VARIABLE(cursor_name, ':X', 3500); 

or

BIND_VARIABLE (cursor_name, 'X', 3500);

The length of the bind variable name should be <=30 bytes.

---

CLOSE_CURSOR Procedure

This procedure closes a given cursor.

Syntax

DBMS_SQL.CLOSE_CURSOR (
   c    IN OUT INTEGER);

Pragmas

pragma restrict_references(close_cursor,RNDS,WNDS);

Parameters

---

COLUMN_VALUE Procedure

This procedure returns the value of the cursor element for a given position in a given cursor. This procedure is used to access the data fetched by calling FETCH_ROWS.

Syntax

DBMS_SQL.COLUMN_VALUE (
   c                 IN  INTEGER,
   position          IN  INTEGER,
   value             OUT <datatype> 
 [,column_error      OUT NUMBER] 
 [,actual_length     OUT INTEGER]);

Where square brackets [ ] indicate optional parameters and <datatype> can be any one of the following types:

BINARY_DOUBLE
BINARY_FLOAT
BFILE
BLOB
CLOB CHARACTER SET ANY_CS
DATE
DSINTERVAL_UNCONSTRAINED
NUMBER
TIME_TZ_UNCONSTRAINED
TIME_UNCONSTRAINED
TIMESTAMP_LTZ_UNCONSTRAINED
TIMESTAMP_TZ_UNCONSTRAINED
TIMESTAMP_UNCONSTRAINED
UROWID
VARCHAR2 CHARACTER SET ANY_CS
YMINTERVAL_UNCONSTRAINED
user-defined object types
collections (VARRAYs and nested tables)
REFs
Opaque types

For variables containing CHAR, RAW, and ROWID data, you can use the following variations on the syntax:

DBMS_SQL.COLUMN_VALUE_CHAR (
   c               IN  INTEGER,
   position        IN  INTEGER,
   value           OUT CHAR CHARACTER SET ANY_CS
 [,column_error    OUT NUMBER]
 [,actual_length   OUT INTEGER]);
 
DBMS_SQL.COLUMN_VALUE_RAW (
   c               IN  INTEGER,
   position        IN  INTEGER,
   value           OUT RAW
 [,column_error    OUT NUMBER]
 [,actual_length   OUT INTEGER]);

DBMS_SQL.COLUMN_VALUE_ROWID (
   c               IN  INTEGER,
   position        IN  INTEGER,
   value           OUT ROWID
 [,column_error    OUT NUMBER]
 [,actual_length   OUT INTEGER]);

The following syntax enables the COLUMN_VALUE procedure to accommodate bulk operations:

DBMS_SQL.COLUMN_VALUE( 
   c                 IN             INTEGER, 
   position          IN             INTEGER, 
   <param_name>      IN OUT NOCOPY  <table_type>);  

Where the <param_name> and its corresponding <table_type> can be any one of these matching pairs:

bdbl_tab     Binary_Double_Table
bflt_tab     Binary_Float_Table
bf_tab       Bfile_Table
bl_tab       Blob_Table
cl_tab       Clob_Table
d_tab        Date_Table
ids_tab      Interval_Day_To_Second_Table
iym_tab      Interval_Year_To_Month_Table
n_tab        Number_Table
tm_tab       Time_Table
ttz_tab      Time_With_Time_Zone_Table
tms_tab      Timestamp_Table
tstz_tab     Timestamp_With_ltz_Table;
tstz_tab     Timestamp_With_Time_Zone_Table
ur_tab       Urowid_Table
c_tab        Varchar2_Table

Pragmas

pragma restrict_references(column_value,RNDS,WNDS);

Parameters

Exceptions

INCONSISTENT_TYPE (ORA-06562) is raised if the type of the given OUT parameter value is different from the actual type of the value. This type was the given type when the column was defined by calling procedure DEFINE_COLUMN.

---

COLUMN_VALUE_LONG Procedure

This procedure gets part of the value of a long column.

Syntax

DBMS_SQL.COLUMN_VALUE_LONG (
   c            IN  INTEGER, 
   position     IN  INTEGER, 
   length       IN  INTEGER, 
   offset       IN  INTEGER,
   value        OUT VARCHAR2,
   value_length OUT INTEGER);

Pragmas

pragma restrict_references(column_value_long,RNDS,WNDS);

Parameters

---

DEFINE_ARRAY Procedure

This procedure defines the collection for column into which you want to fetch rows (with a FETCH_ROWS call). This procedure lets you do batch fetching of rows from a single SELECT statement. A single fetch call brings over a number of rows into the PL/SQL aggregate object.

When you fetch the rows, they are copied into DBMS_SQL buffers until you run a COLUMN_VALUE call, at which time the rows are copied into the table that was passed as an argument to the COLUMN_VALUE call.

Scalar and LOB Types for Collections

You can declare a local variable as one of the following table-item types, and then fetch any number of rows into it using DBMS_SQL. (These are the same types as you can specify for the BIND_ARRAY procedure.)

TYPE binary_double_table 
                    IS TABLE OF BINARY_DOUBLE  INDEX BY BINARY_INTEGER;
TYPE binary_float_table 
                    IS TABLE OF BINARY_FLOAT   INDEX BY BINARY_INTEGER;
TYPE bfile_table    IS TABLE OF BFILE          INDEX BY BINARY_INTEGER;
TYPE blob_table     IS TABLE OF BLOB           INDEX BY BINARY_INTEGER;
TYPE clob_table     IS TABLE OF CLOB           INDEX BY BINARY_INTEGER;
TYPE date_table     IS TABLE OF DATE           INDEX BY BINARY_INTEGER;
TYPE interval_day_to_second_Table 
                    IS TABLE OF dsinterval_unconstrained 
                                               INDEX BY BINARY_INTEGER;
TYPE interval_year_to_MONTH_Table 
                    IS TABLE OF yminterval_unconstrained 
                                               INDEX BY BINARY_INTEGER;
TYPE number_table   IS TABLE OF NUMBER         INDEX BY BINARY_INTEGER;
TYPE time_table     IS TABLE OF time_unconstrained           
                                               INDEX BY BINARY_INTEGER;
TYPE time_with_time_zone_table 
                    IS TABLE OF time_tz_unconstrained 
                                               INDEX BY BINARY_INTEGER;
TYPE timestamp_table 
                    IS TABLE OF timestamp_unconstrained   
                                               INDEX BY BINARY_INTEGER;
TYPE timestamp_with_ltz_Table 
                    IS TABLE OF timestamp_ltz_unconstrained 
                                               INDEX BY BINARY_INTEGER;
TYPE timestamp_with_time_zone_Table 
                    IS TABLE OF timestamp_tz_unconstrained 
                                               INDEX BY BINARY_INTEGER;
TYPE urowid_table   IS TABLE OF UROWID         INDEX BY BINARY_INTEGER;
TYPE varchar2_table IS TABLE OF VARCHAR2(2000) INDEX BY BINARY_INTEGER;

<tm_tab>   Time_Table
<ttz_tab>  Time_With_Time_Zone_Table
<tms_tab>  Timestamp_Table
<tstz_tab> Timestamp_With_ltz_Table;
<tstz_tab> Timestamp_With_Time_Zone_Table
<ids_tab>  Interval_Day_To_Second_Table
<iym_tab>  Interval_Year_To_Month_Table

Syntax

DBMS_SQL.DEFINE_ARRAY (
   c           IN INTEGER, 
   position    IN INTEGER,
   <table_variable>    IN <datatype> 
   cnt         IN INTEGER, 
   lower_bnd   IN INTEGER);

Where <table_variable> and its corresponding <datatype> can be any one of the following matching pairs:

<clob_tab>     Clob_Table
<bflt_tab>     Binary_Float_Table
<bdbl_tab>     Binary_Double_Table
<blob_tab>     Blob_Table
<bfile_tab>    Bfile_Table
<date_tab>     Date_Table
<num_tab>      Number_Table
<urowid_tab>   Urowid_Table
<vchr2_tab>    Varchar2_Table

Note that DEFINE_ARRAY is overloaded to accept different datatypes.

Pragmas

pragma restrict_references(define_array,RNDS,WNDS);

The subsequent FETCH_ROWS call fetch "count" rows. When the COLUMN_VALUE call is made, these rows are placed in positions lower_bnd, lower_bnd+1, lower_bnd+2, and so on. While there are still rows coming, the user keeps issuing FETCH_ROWS/COLUMN_VALUE calls. The rows keep accumulating in the table specified as an argument in the COLUMN_VALUE call.

Parameters

Usage Notes

The count (cnt) must be an integer greater than zero; otherwise an exception is raised. The lower_bnd can be positive, negative, or zero. A query on which a DEFINE_ARRAY call was issued cannot contain array binds.

Examples

PROCEDURE BULK_PLSQL(deptid NUMBER)
    TYPE namelist IS TABLE OF employees.last_name%TYPE;
    TYPE sallist IS TABLE OF employees.salary%TYPE;
    names    namelist;
    sals     sallist;
    c        NUMBER;
    r        NUMBER;
    sql_stmt VARCHAR2(32767) :=
        'SELECT last_name, salary FROM employees WHERE department_id = :b1';
 
BEGIN
    c := DBMS_SQL.OPEN_CURSOR;
    DBMS_SQL.PARSE(c, sql_stmt, dbms_sql.native);
 
    DBMS_SQL.BIND_VARIABLE(c, 'b1', deptid);
 
    DBMS_SQL.DEFINE_ARRAY(c, 1, names, 5);
    DBMS_SQL.DEFINE_ARRAY(c, 2, sals, 5);
 
    r := DBMS_SQL.EXECUTE(c);
 
    LOOP
      r := DBMS_SQL.FETCH_ROWS(c);
      DBMS_SQL.COLUMN_VALUE(c, 1, names);
      DBMS_SQL.COLUMN_VALUE(c, 2, sals);
      EXIT WHEN r != 5;
    END LOOP;
 
    DBMS_SQL.CLOSE_CURSOR(c);
 
    -- loop through the names and sals collections
    FOR i IN names.FIRST .. names.LAST  LOOP
      DBMS_OUTPUT.PUT_LINE('Name = ' || names(i) || ', salary = ' || sals(i));
    END LOOP;
END;
/

---

DEFINE_COLUMN Procedures

This procedure defines a column to be selected from the given cursor. This procedure is only used with SELECT cursors.

The column being defined is identified by its relative position in the SELECT list of the statement in the given cursor. The type of the COLUMN value determines the type of the column being defined.

See also the DEFINE_COLUMN_CHAR Procedure, DEFINE_COLUMN_LONG Procedure, DEFINE_COLUMN_RAW Procedure and DEFINE_COLUMN_ROWID Procedure.

Syntax

DBMS_SQL.DEFINE_COLUMN (
   c              IN INTEGER,
   position       IN INTEGER,
   column         IN <datatype>)

Where <datatype> can be any one of the following types:

BINARY_DOUBLE
BINARY_FLOAT
BFILE
BLOB
CLOB CHARACTER SET ANY_CS
DATE
DSINTERVAL_UNCONSTRAINED
NUMBER
TIME_UNCONSTRAINED
TIME_TZ_UNCONSTRAINED
TIMESTAMP_LTZ_UNCONSTRAINED
TIMESTAMP_TZ_UNCONSTRAINED
TIMESTAMP_UNCONSTRAINED
UROWID
VARCHAR2 CHARACTER SET ANY_CS
YMINTERVAL_UNCONSTRAINED
user-defined object types
collections (VARRAYs and nested tables)
REFs
Opaque types

Note that DEFINE_COLUMN is overloaded to accept different datatypes.

The following syntax is also supported for the DEFINE_COLUMN procedure:

DBMS_SQL.DEFINE_COLUMN (
   c              IN INTEGER,
   position       IN INTEGER,
   column         IN VARCHAR2 CHARACTER SET ANY_CS,
   column_size    IN INTEGER),
   urowid         IN INTEGER;

Pragmas

pragma restrict_references(define_column,RNDS,WNDS);

Parameters

Usage Notes

When using character length semantics the maximum number of bytes that can be returned for a column value of type VARCHAR2 is calculated as: column_size * maximum character byte size for the current characterset. For example, specifying the column_size as 10 means that a maximum of 30 (10*3) bytes can be returned when using character length semantics with a UTF8 character set regardless of the number of characters this represents.

---

DEFINE_COLUMN_CHAR Procedure

This procedure defines a column with CHAR data to be selected from the given cursor. This procedure is only used with SELECT cursors.

The column being defined is identified by its relative position in the SELECT list of the statement in the given cursor. The type of the COLUMN value determines the type of the column being defined.

See also the DEFINE_COLUMN Procedures, DEFINE_COLUMN_LONG Procedure, DEFINE_COLUMN_RAW Procedure and DEFINE_COLUMN_ROWID Procedure.

Syntax

DBMS_SQL.DEFINE_COLUMN_CHAR (
   c              IN INTEGER,
   position       IN INTEGER,
   column         IN CHAR CHARACTER SET ANY_CS,
   column_size    IN INTEGER);

Pragmas

pragma restrict_references(define_column,RNDS,WNDS);

Parameters

---

DEFINE_COLUMN_LONG Procedure

This procedure defines a LONG column for a SELECT cursor. The column being defined is identified by its relative position in the SELECT list of the statement for the given cursor. The type of the COLUMN value determines the type of the column being defined.

See also the DEFINE_COLUMN Procedures, DEFINE_COLUMN_CHAR Procedure, DEFINE_COLUMN_RAW Procedure and DEFINE_COLUMN_ROWID Procedure.

Syntax

DBMS_SQL.DEFINE_COLUMN_LONG (
   c              IN INTEGER,
   position       IN INTEGER); 

Parameters

---

DEFINE_COLUMN_RAW Procedure

This procedure defines a column of type RAW to be selected from the given cursor. This procedure is only used with SELECT cursors.

The column being defined is identified by its relative position in the SELECT list of the statement in the given cursor. The type of the COLUMN value determines the type of the column being defined.

See also the DEFINE_COLUMN Procedures, DEFINE_COLUMN_CHAR Procedure, DEFINE_COLUMN_LONG Procedure and DEFINE_COLUMN_ROWID Procedure.

Syntax

DBMS_SQL.DEFINE_COLUMN_RAW (
   c              IN INTEGER,
   position       IN INTEGER,
   column         IN RAW,
   column_size    IN INTEGER);

Pragmas

pragma restrict_references(define_column,RNDS,WNDS);

Parameters

---

DEFINE_COLUMN_ROWID Procedure

This procedure defines a column of type ROWID to be selected from the given cursor. This procedure is only used with SELECT cursors.

The column being defined is identified by its relative position in the SELECT list of the statement in the given cursor. The type of the COLUMN value determines the type of the column being defined.

See also the DEFINE_COLUMN Procedures, DEFINE_COLUMN_CHAR Procedure, DEFINE_COLUMN_LONG Procedure and DEFINE_COLUMN_RAW Procedure.

Syntax

DBMS_SQL.DEFINE_COLUMN_ROWID (
   c              IN INTEGER,
   position       IN INTEGER,
   column         IN ROWID); 

Pragmas

pragma restrict_references(define_column,RNDS,WNDS);

Parameters

---

DESCRIBE_COLUMNS Procedure

This procedure describes the columns for a cursor opened and parsed through DBMS_SQL.

Syntax

DBMS_SQL.DESCRIBE_COLUMNS ( 
   c              IN  INTEGER, 
   col_cnt        OUT INTEGER, 
   desc_t         OUT DESC_TAB);

Parameters

---

DESCRIBE_COLUMNS2 Procedure

This function describes the specified column. This is an alternative to DESCRIBE_COLUMNS Procedure.

Syntax

DBMS_SQL.DESCRIBE_COLUMNS2 ( 
   c              IN  INTEGER, 
   col_cnt        OUT INTEGER, 
   desc_t         OUT DESC_TAB2);

Pragmas

PRAGMA RESTRICT_REFERENCES(describe_columns2,WNDS);

Parameters

---

DESCRIBE_COLUMNS3 Procedure

This function describes the specified column. This is an alternative to DESCRIBE_COLUMNS Procedure.

Syntax

DBMS_SQL.DESCRIBE_COLUMNS3 ( 
   c              IN  INTEGER, 
   col_cnt        OUT INTEGER, 
   desc_t         OUT DESC_TAB3);

Pragmas

PRAGMA RESTRICT_REFERENCES(describe_columns3,WNDS);

Parameters

Usage Notes

The cursor passed in by the cursor ID has to be OPENed and PARSEd, otherwise an "invalid cursor id" error is raised.

Examples

CREATE TYPE PROJECT_T AS OBJECT
      ( projname          VARCHAR2(20),
        mgr               VARCHAR2(20))
/
 
CREATE TABLE projecttab(deptno NUMBER, project HR.PROJECT_T)
/
 
DECLARE
  curid      NUMBER;
  desctab    DBMS_SQL.DESC_TAB3;
  colcnt     NUMBER;
  sql_stmt   VARCHAR2(200) := 'select * from projecttab';
BEGIN
 
    curid := DBMS_SQL.OPEN_CURSOR;
 
    DBMS_SQL.PARSE(curid, sql_stmt, DBMS_SQL.NATIVE);
 
    DBMS_SQL.DESCRIBE_COLUMNS3(curid, colcnt, desctab);
 
    FOR i IN 1 .. colcnt LOOP
      IF desctab(i).col_type = 109 THEN
        DBMS_OUTPUT.PUT(desctab(i).col_name || ' is user-defined type: ');
        DBMS_OUTPUT.PUT_LINE(desctab(i).col_schema_name || '.' ||
                             desctab(i).col_type_name);
      END IF;
    END LOOP;
 
    DBMS_SQL.CLOSE_CURSOR(curid);
END;
/
 
Output:
 
PROJECT is user-defined type: HR.PROJECT_T

---

EXECUTE Function

This function executes a given cursor. This function accepts the ID number of the cursor and returns the number of rows processed. The return value is only valid for INSERT, UPDATE, and DELETE statements; for other types of statements, including DDL, the return value is undefined and should be ignored.

Syntax

DBMS_SQL.EXECUTE (
   c   IN INTEGER)
  RETURN INTEGER;

Parameters

Usage Notes

The DBMS_SQL cursor that is returned by the TO_CURSOR_NUMBER Function performs in the same way as a DBMS_SQL cursor that has already been executed. Consequently, calling EXECUTE for this cursor will cause an error.

---

EXECUTE_AND_FETCH Function

This function executes the given cursor and fetches rows. This function provides the same functionality as calling EXECUTE and then calling FETCH_ROWS. Calling EXECUTE_AND_FETCH instead, however, may reduce the number of network round-trips when used against a remote database.

The EXECUTE_AND_FETCH function returns the number of rows actually fetched.

Syntax

DBMS_SQL.EXECUTE_AND_FETCH (
   c              IN INTEGER,
   exact          IN BOOLEAN DEFAULT FALSE)
  RETURN INTEGER;

Pragmas

pragma restrict_references(execute_and_fetch,WNDS);

Parameters

---

FETCH_ROWS Function

This function fetches a row from a given cursor. You can call FETCH_ROWS repeatedly as long as there are rows remaining to be fetched. These rows are retrieved into a buffer, and must be read by calling COLUMN_VALUE, for each column, after each call to FETCH_ROWS.

The FETCH_ROWS function accepts the ID number of the cursor to fetch, and returns the number of rows actually fetched.

Syntax

DBMS_SQL.FETCH_ROWS (
   c              IN INTEGER)
  RETURN INTEGER;

Pragmas

pragma restrict_references(fetch_rows,WNDS);

Parameters

---

IS_OPEN Function

This function checks to see if the given cursor is currently open.

Syntax

DBMS_SQL.IS_OPEN (
   c              IN INTEGER)
  RETURN BOOLEAN;

Pragmas

pragma restrict_references(is_open,RNDS,WNDS);

Parameters

Return Values

Returns TRUE for any cursor number that has been opened but not closed, and FALSE for a NULL cursor number. Note that the CLOSE_CURSOR Procedure Procedure NULLs out the cursor variable passed to it.

Exceptions

ORA-29471 DBMS_SQL access denied: This is raised if an invalid cursor ID number is detected. Once a session has encountered and reported this error, every subsequent DBMS_SQL call in the same session will raise this error, meaning that DBMS_SQL is non-operational for this session.

---

LAST_ERROR_POSITION Function

This function returns the byte offset in the SQL statement text where the error occurred. The first character in the SQL statement is at position 0.

Syntax

DBMS_SQL.LAST_ERROR_POSITION 
   RETURN INTEGER;

Pragmas

pragma restrict_references(last_error_position,RNDS,WNDS);

Usage Notes

Call this function after a PARSE call, before any other DBMS_SQL procedures or functions are called.

---

LAST_ROW_COUNT Function

This function returns the cumulative count of the number of rows fetched.

Syntax

DBMS_SQL.LAST_ROW_COUNT 
   RETURN INTEGER;

Pragmas

pragma restrict_references(last_row_count,RNDS,WNDS);

Usage Notes

Call this function after a FETCH_ROWS or an EXECUTE_AND_FETCH call. If called after an EXECUTE call, then the value returned is zero.

---

LAST_ROW_ID Function

This function returns the ROWID of the last row processed.

Syntax

DBMS_SQL.LAST_ROW_ID 
   RETURN ROWID;

Pragmas

pragma restrict_references(last_row_id,RNDS,WNDS);

Usage Notes

Call this function after a FETCH_ROWS or an EXECUTE_AND_FETCH call.

---

LAST_SQL_FUNCTION_CODE Function

This function returns the SQL function code for the statement. These codes are listed in the Oracle Call Interface Programmer's Guide.

Syntax

DBMS_SQL.LAST_SQL_FUNCTION_CODE 
   RETURN INTEGER;

Pragmas

pragma restrict_references(last_sql_function_code,RNDS,WNDS);

Usage Notes

You should call this function immediately after the SQL statement is run; otherwise, the return value is undefined.

---

OPEN_CURSOR Function

This procedure opens a new cursor. The second overload takes a security_level parameter to apply fine-grained control to the security of the opened cursor.

When you no longer need this cursor, you must close it explicitly by calling the CLOSE_CURSOR Procedure.

Syntax

DBMS_SQL.OPEN_CURSOR 
  RETURN INTEGER;

DBMS_SQL.OPEN_CURSOR (
   security_level   IN   INTEGER) 
  RETURN INTEGER;

Parameters

Pragmas

pragma restrict_references(open_cursor,RNDS,WNDS);

Return Values

This function returns the cursor ID number of the new cursor.

Usage Notes

You can use cursors to run the same SQL statement repeatedly or to run a new SQL statement. When a cursor is reused, the contents of the corresponding cursor data area are reset when the new SQL statement is parsed. It is never necessary to close and reopen a cursor before reusing it.

---

PARSE Procedures

This procedure parses the given statement in the given cursor. All statements are parsed immediately. In addition, DDL statements are run immediately when parsed.

There are three versions of the PARSE procedure:

• Taking a VARCHAR2 statement as an argument

• Taking VARCHAR2a, table of VARCHAR2(32767), as an argument. The VARCHAR2A overload version of the procedure concatenates elements of a PL/SQL table statement and parses the resulting string. You can use this procedure to parse a statement that is longer than the limit for a single VARCHAR2 variable by splitting up the statement.

• Taking a CLOB statement as an argument. You can use the CLOB overload version of the parse procedure to parse a SQL statement larger than 32K bytes.

Syntax

DBMS_SQL.PARSE (
   c                           IN   INTEGER,
   statement                   IN   VARCHAR2,
   language_flag               IN   INTEGER,
   edition                     IN   VARCHAR2 DEFAULT NULL,
   apply_crossedition_trigger  IN   VARCHAR2 DEFAULT NULL,
   fire_apply_trigger          IN   BOOLEAN DEFAULT TRUE);

DBMS_SQL.PARSE (
   c                           IN   INTEGER,
   statement                   IN   CLOB,
   language_flag               IN   INTEGER,
   edition                     IN   VARCHAR2 DEFAULT NULL,
   apply_crossedition_trigger  IN   VARCHAR2 DEFAULT NULL,
   fire_apply_trigger          IN   BOOLEAN DEFAULT TRUE);

DBMS_SQL.PARSE (
   c                           IN   INTEGER, 
   statement                   IN   VARCHAR2A,
   lb                          IN   INTEGER, 
   ub                          IN   INTEGER,
   lfflg                       IN   BOOLEAN, 
   language_flag               IN   INTEGER,
   edition                     IN   VARCHAR2 DEFAULT NULL,
   apply_crossedition_trigger  IN   VARCHAR2 DEFAULT NULL,
   fire_apply_trigger          IN   BOOLEAN DEFAULT TRUE);

Parameters

Usage Notes

• Using DBMS_SQL to dynamically run DDL statements can result in the program hanging. For example, a call to a procedure in a package results in the package being locked until the execution returns to the user side. Any operation that results in a conflicting lock, such as dynamically trying to drop the package before the first lock is released, results in a hang.

• Because client-side code cannot reference remote package variables or constants, you must explicitly use the values of the constants.

  For example, the following code does not compile on the client:

  DBMS_SQL.PARSE(cur_hdl, stmt_str, DBMS_SQL.NATIVE); -- uses constant DBMS_SQL.NATIVE

  The following code works on the client, because the argument is explicitly provided:

  DBMS_SQL.PARSE(cur_hdl, stmt_str, 1); -- compiles on the client

• The VARCHAR2S type is currently supported for backward compatibility of legacy code. However, you are advised to use VARCHAR2A both for its superior capability and because VARCHAR2S will be deprecated in a future release.

• To parse SQL statements larger than 32 KB, the new CLOB overload version of the PARSE procedure can be used instead of the VARCHAR2A overload

Exceptions

If you create a type/procedure/function/package using DBMS_SQL that has compilation warnings, an ORA-24344 exception is raised, and the procedure is still created.

---

TO_CURSOR_NUMBER Function

This function takes an OPENed strongly or weakly-typed ref cursor and transforms it into a DBMS_SQL cursor number.

Syntax

DBMS_SQL.TO_CURSOR_NUMBER(
   rc IN OUT SYS_REFCURSOR)
  RETURN INTEGER;

Parameters

Return Values

Returns a DBMS_SQL manageable cursor number transformed from a REF CURSOR

Usage Notes

• The REF CURSOR passed in has to be OPENed, otherwise an error is raised.Once the REF CURSOR is transformed into a DBMS_SQL cursor number, the REF CURSOR is no longer accessible by any native dynamic SQL operations.Toggle between REF CURSOR and DBMS_SQL cursor number after started to fetch is not allowed, and an error is raised.

• The DBMS_SQL cursor that is returned by this subprogram performs in the same way as a DBMS_SQL cursor that has already been executed.

Examples

CREATE OR REPLACE PROCEDURE DO_QUERY(sql_stmt VARCHAR2) IS
  TYPE CurType IS REF CURSOR;
  src_cur         CurType;
  curid           NUMBER;
  desctab         DBMS_SQL.DESC_TAB;
  colcnt          NUMBER;
  namevar         VARCHAR2(50);
  numvar          NUMBER;
  datevar         DATE;
  empno           NUMBER := 100;
BEGIN
 
 
    -- sql_stmt := 'select ...... from employees where employee_id = :b1';
    OPEN src_cur FOR sql_stmt USING empno;
 
    -- Switch from native dynamic SQL to DBMS_SQL
    curid := DBMS_SQL.TO_CURSORID(src_cur);
 
    DBMS_SQL.DESCRIBE_COLUMNS(curid, colcnt, desctab);
 
    -- Define columns
    FOR i IN 1 .. colcnt LOOP
        IF desctab(i).col_type = 2 THEN
           DBMS_SQL.DEFINE_COLUMN(curid, i, numvar);
        ELSIF desctab(i).col_type = 12 THEN
            DBMS_SQL.DEFINE_COLUMN(curid, i, datevar);
.......
         ELSE
            DBMS_SQL.DEFINE_COLUMN(curid, i, namevar);
         END IF;
    END LOOP;
 
  -- Fetch Rows
    WHILE DBMS_SQL.FETCH_ROWS(curid) > 0 LOOP
        FOR i IN 1 .. colcnt LOOP
          IF (desctab(i).col_type = 1) THEN
            DBMS_SQL.COLUMN_VALUE(curid, i, namevar);
         ELSIF (desctab(i).col_type = 2) THEN
            DBMS_SQL.COLUMN_VALUE(curid, i, numvar);
          ELSIF (desctab(i).col_type = 12) THEN
            DBMS_SQL.COLUMN_VALUE(curid, i, datevar);
....
          END IF;
        END LOOP;
    END LOOP;
 
    DBMS_SQL.CLOSE_CURSOR(curid);
END;
/ 

---

TO_REFCURSOR Function

This function takes an OPENed, PARSEd, and EXECUTEd cursor and transforms/migrates it into a PL/SQL manageable REF CURSOR (a weakly-typed cursor) that can be consumed by PL/SQL native dynamic SQLswitched to use native dynamic SQL. This subprogram is only used with SELECT cursors.

Syntax

DBMS_SQL.TO_REFCURSOR(
   cursor_number IN  INTEGER)
  RETURN SYS_REFCURSOR;

Parameters

Return Values

Returns a PL/SQL REF CURSOR transformed from a DBMS_SQL cursor number.

Usage Notes

• The cursor passed in by the cursor_number has to be OPENed, PARSEd, and EXECUTEd; otherwise an error is raised.Once the cursor_number is transformed into a REF CURSOR, the cursor_number is no longer accessible by any DBMS_SQL operations.After a cursor_number is transformed into a REF CURSOR, using DBMS_SQL.IS_OPEN to check to see if the cursor_number is still open results in an error.Toggle between REF CURSOR and DBMS_SQL cursor number after started to fetch is not allowed, and an error is raised.

Examples

CREATE OR REPLACE PROCEDURE DO_QUERY(mgr_id NUMBER) IS
  TYPE CurType IS REF CURSOR;
  src_cur         CurType;
  curid           NUMBER;
  sql_stmt        VARCHAR2(200);
  ret             INTEGER;
  empnos          DBMS_SQL.Number_Table;
  depts           DBMS_SQL.Number_Table;
BEGIN

  -- DBMS_SQL.OPEN_CURSOR
  curid := DBMS_SQL.OPEN_CURSOR;
 
  sql_stmt :=    'SELECT EMPLOYEE_ID, DEPARTMENT_ID from employees where MANAGER_ID = :b1';

  DBMS_SQL.PARSE(curid, sql_stmt, DBMS_SQL.NATIVE);
  DBMS_SQL.BIND_VARIABLE(curid, 'b1', mgr_id);
  ret := DBMS_SQL.EXECUTE(curid);

  -- Switch from DBMS_SQL to native dynamic SQL
  src_cur := DBMS_SQL.TO_REFCURSOR(curid);

  -- Fetch with native dynamic SQL
  FETCH src_cur BULK COLLECT INTO empnos, depts;

  IF empnos.COUNT > 0 THEN
    DBMS_OUTPUT.PUT_LINE('EMPNO DEPTNO');
    DBMS_OUTPUT.PUT_LINE('----- ------');
    -- Loop through the empnos and depts collections
    FOR i IN 1 .. empnos.COUNT LOOP
      DBMS_OUTPUT.PUT_LINE(empnos(i) || '   ' || depts(i));
    END LOOP;
  END IF;
   -- Close cursor
  CLOSE src_cur;
END;
/ 

---

VARIABLE_VALUE Procedures

This procedure returns the value of the named variable for a given cursor. It is used to return the values of bind variables inside PL/SQL blocks or DML statements with returning clause.

Syntax

DBMS_SQL.VARIABLE_VALUE (
   c               IN  INTEGER,
   name            IN  VARCHAR2,
   value           OUT NOCOPY <datatype>);
 

Where <datatype> can be any one of the following types:

BINARY_DOUBLE
BINARY_FLOAT
BFILE
BLOB
CLOB CHARACTER SET ANY_CS
DATE
DSINTERVAL_UNCONSTRAINED
NUMBER
TIME_TZ_UNCONSTRAINED
TIME_UNCONSTRAINED
TIMESTAMP_LTZ_UNCONSTRAINED
TIMESTAMP_TZ_UNCONSTRAINED
TIMESTAMP_UNCONSTRAINED
UROWID
VARCHAR2 CHARACTER SET ANY_CS
YMINTERVAL_UNCONSTRAINED
user-defined object types
collections (VARRAYs and nested tables)
REFs
Opaque types

For variables containing CHAR, RAW, and ROWID data, you can use the following variations on the syntax:

DBMS_SQL.VARIABLE_VALUE_CHAR (
   c               IN  INTEGER,
   name            IN  VARCHAR2,
   value           OUT CHAR CHARACTER SET ANY_CS);

DBMS_SQL.VARIABLE_VALUE_RAW (
   c               IN  INTEGER,
   name            IN  VARCHAR2,
   value           OUT RAW);

DBMS_SQL.VARIABLE_VALUE_ROWID (
   c               IN  INTEGER,
   name            IN  VARCHAR2,
   value           OUT ROWID);

The following syntax enables the VARIABLE_VALUE procedure to accommodate bulk operations:

DBMS_SQL.VARIABLE_VALUE ( 
   c                 IN   INTEGER, 
   name              IN   VARCHAR2,
   value             OUT NOCOPY <table_type>); 

For bulk operations, <table_type> can be:

Binary_Double_Table
Binary_Float_Table
Bfile_Table
Blob_Table
Clob_Table
Date_Table
Interval_Day_To_Second_Table
Interval_Year_To_Month_Table
Number_Table
Time_Table
Time_With_Time_Zone_Table
Timestamp_Table
Timestamp_With_ltz_Table;
Timestamp_With_Time_Zone_Table
Urowid_Table
Varchar2_Table

Pragmas

pragma restrict_references(variable_value,RNDS,WNDS);

Parameters