B Using Oracle ODBC Driver

B.1 Features Not Supported

Oracle ODBC Driver does not support the following ODBC 3.0 features:

• Interval data types

• SQL_C_UBIGINT and SQL_C_SBIGINT C data type identifiers

• Shared connections

• Shared environments

• The SQL_LOGIN_TIMEOUT attribute of SQLSetConnectAttr

• The expired password option

Oracle ODBC Driver does not support the SQL functions listed in the following table:

B.2 Implementation of Data Types

This section discusses the DATE, TIMESTAMP, and floating point data types.

DATE and TIMESTAMP

The semantics of Oracle DATE and TIMESTAMP data types do not correspond exactly with the ODBC data types with the same names. The Oracle DATE data type contains both date and time information. The SQL_DATE data type contains only date information. The Oracle TIMESTAMP data type also contains date and time information, but it has greater precision in fractional seconds. Oracle ODBC Driver reports the data types of both Oracle DATE and TIMESTAMP columns as SQL_TIMESTAMP to prevent information loss. Similarly, Oracle ODBC Driver binds SQL_TIMESTAMP parameters as Oracle TIMESTAMP values.

Floating Point Data Types

When connected to an Oracle Database 11g Release 2 (11.2) or later, Oracle ODBC Driver maps the Oracle floating point data types BINARY_FLOAT and BINARY_DOUBLE to the ODBC data types SQL_REAL and SQL_DOUBLE, respectively. In earlier releases, SQL_REAL and SQL_DOUBLE mapped to the generic Oracle numeric data type.

B.3 Limitations on Data Types

Oracle ODBC Driver and Oracle Database impose limitations on data types. The following table describes these limitations:

B.4 Format of the Connection String for the SQLDriverConnect Function

The SQLDriverConnect function is one of the functions implemented by Oracle ODBC Driver. The following table describes the keywords that you can include in the connection string argument of the SQLDriverConnect function call:

B.5 Reducing Lock Timeout in a Program

Oracle Database waits indefinitely for lock conflicts between transactions to be resolved. However, you can limit the amount of time that Oracle Database waits for locks to be resolved. To do this, set the SQL_ATTR_QUERY_TIMEOUT attribute of the ODBC SQLSetStmtAttr function while calling this function before connecting to the data source.

B.6 Linking ODBC Applications

When you link the program, you must link it with the Driver Manager library, libodbc.so.

B.7 Obtaining Information About ROWIDs

The ODBC SQLSpecialColumns function returns information about the columns in a table. When used with Oracle ODBC Driver, it returns information about the Oracle ROWIDs associated with an Oracle table.

B.8 ROWIDs in a WHERE Clause

ROWIDs may be used in the WHERE clause of an SQL statement. However, the ROWID value must be presented in a parameter marker.

B.9 Enabling Result Sets

Oracle reference cursors, also known as result sets, enable an application to retrieve data using stored procedures and stored functions. The following information describes how to use reference cursors to enable result sets through ODBC:

• You must use the ODBC syntax for calling stored procedures. Native PL/SQL is not supported through ODBC. The following code sample identifies how to call the procedure or function without a package and within a package. The package name in this case is RSET.

  Procedure call:
  {CALL Example1(?)}
  {CALL RSET.Example1(?)}
  Function Call:
  {? = CALL Example1(?)}
  {? = CALL RSET.Example1(?)} 
  

• The PL/SQL reference cursor parameters are omitted when calling the procedure. For example, assume procedure Example2 is defined to have four parameters. Parameters 1 and 3 are reference cursor parameters and parameters 2 and 4 are character strings. The call is specified as:

  {CALL RSET.Example2("Literal 1", "Literal 2")}
  

The following sample application shows how to return a result set by using Oracle ODBC Driver:

/*
* Sample Application using Oracle reference cursors through ODBC
*
* Assumptions:
*
* 1) Oracle Sample database is present with data loaded for the EMP table.
*
* 2) Two fields are referenced from the EMP table, ename and mgr.
*
* 3) A data source has been setup to access the sample database.
*
*
* Program Description:
*
* Abstract:
*
* This program demonstrates how to return result sets using
* Oracle stored procedures
*
* Details:
*
* This program:
* Creates an ODBC connection to the database.
* Creates a Packaged Procedure containing two result sets.
* Executes the procedure and retrieves the data from both result sets.
* Displays the data to the user.
* Deletes the package then logs the user out of the database.
*
*
* The following is the actual PL/SQL this code generates to
* create the stored procedures.
*  
DROP PACKAGE   ODBCRefCur;
CREATE PACKAGE ODBCRefCur AS
     TYPE ename_cur IS REF CURSOR;
     TYPE mgr_cur   IS REF CURSOR;
PROCEDURE EmpCurs(Ename IN OUT ename_cur, Mgr IN OUT mgr_cur, pjob IN VARCHAR2); 

END; 

/
CREATE PACKAGE BODY ODBCRefCur AS
PROCEDURE EmpCurs(Ename IN OUT ename_cur, Mgr IN OUT mgr_cur, pjob IN VARCHAR2)
     AS
       BEGIN
          IF NOT Ename%ISOPEN
          THEN
              OPEN Ename for SELECT ename from emp;
          END IF; 

          IF NOT Mgr%ISOPEN
          THEN
              OPEN Mgr for SELECT mgr from emp where job = pjob;
          END IF;
       END;
END;
/ 


*
*  End PL/SQL for Reference Cursor. 
*/

/*
 * Include Files
 */
#include <stdio.h>
#include <sql.h>
#include <sqlext.h>
/*
 * Defines
 */
#define JOB_LEN 9
#define DATA_LEN 100
#define SQL_STMT_LEN 500
/*
 * Procedures
 */
void DisplayError( SWORD HandleType, SQLHANDLE hHandle, char *Module );
/*
 * Main Program
 */
int main()
{
SQLHENV hEnv;
SQLHDBC hDbc;
SQLHSTMT hStmt;
SQLRETURN rc;
char *DefUserName ="scott";
char *DefPassWord ="tiger";
SQLCHAR ServerName[DATA_LEN];
SQLCHAR *pServerName=ServerName;
SQLCHAR UserName[DATA_LEN];
SQLCHAR *pUserName=UserName;
SQLCHAR PassWord[DATA_LEN];
SQLCHAR *pPassWord=PassWord;
char Data[DATA_LEN];
SQLINTEGER DataLen;
char error[DATA_LEN];
char *charptr;
SQLCHAR SqlStmt[SQL_STMT_LEN];
SQLCHAR *pSqlStmt=SqlStmt;
char *pSalesMan = "SALESMAN";
SQLINTEGER sqlnts=SQL_NTS;
/*
 * Allocate the Environment Handle
 */
rc = SQLAllocHandle( SQL_HANDLE_ENV, SQL_NULL_HANDLE, &hEnv );
if (rc != SQL_SUCCESS)
{
  printf( "Cannot Allocate Environment Handle\n");
  printf( "\nHit Return to Exit\n");
  charptr = gets ((char *)error);
  exit(1);
}
/*
 * Set the ODBC Version
 */
rc = SQLSetEnvAttr( hEnv,SQL_ATTR_ODBC_VERSION,(void *)SQL_OV_ODBC3,0);
if (rc != SQL_SUCCESS)
{
  printf( "Cannot Set ODBC Version\n");
  printf( "\nHit Return to Exit\n");
  charptr = gets ((char *)error);
  exit(1);
}
/*
 * Allocate the Connection handle
 */
rc = SQLAllocHandle( SQL_HANDLE_DBC, hEnv, &hDbc );
if (rc != SQL_SUCCESS)
{
  printf( "Cannot Allocate Connection Handle\n");
  printf( "\nHit Return to Exit\n");
  charptr = gets ((char *)error);
  exit(1);
}
/*
 * Get User Information
 */
strcpy ((char *) pUserName, DefUserName );
strcpy ((char *) pPassWord, DefPassWord );
/*
 * Data Source name
 */
printf( "\nEnter the ODBC Data Source Name\n" );
charptr = gets ((char *) ServerName);
/*
 * User Name
 */
printf ( "\nEnter User Name Default [%s]\n", pUserName);
charptr = gets ((char *) UserName);
if (*charptr == '\0')
{
  strcpy ((char *) pUserName, (char *) DefUserName );
}
/*
 * Password
 */
printf ( "\nEnter Password Default [%s]\n", pPassWord);
charptr = gets ((char *)PassWord);
if (*charptr == '\0')
{
  strcpy ((char *) pPassWord, (char *) DefPassWord );
}
/*
 * Connection to the database
 */
rc = SQLConnect( hDbc,pServerName,(SQLSMALLINT) strlen((char  *)pServerName),pUserName,(SQLSMALLINT) strlen((char *)pUserName),pPassWord,(SQLSMALLINT) strlen((char *)pPassWord));
if (rc != SQL_SUCCESS)
{
  DisplayError(SQL_HANDLE_DBC, hDbc, "SQLConnect");
}
/*
 * Allocate a Statement
 */
rc = SQLAllocHandle( SQL_HANDLE_STMT, hDbc, &hStmt );
if (rc != SQL_SUCCESS)
{
  printf( "Cannot Allocate Statement Handle\n");
  printf( "\nHit Return to Exit\n");
  charptr = gets ((char *)error);
  exit(1);
}
/*
 * Drop the Package
 */
strcpy( (char *) pSqlStmt, "DROP PACKAGE ODBCRefCur");
rc = SQLExecDirect(hStmt, pSqlStmt, strlen((char *)pSqlStmt));
/*
 * Create the Package Header
 */
strcpy( (char *) pSqlStmt, "CREATE PACKAGE ODBCRefCur AS\n");
strcat( (char *) pSqlStmt, " TYPE ename_cur IS REF CURSOR;\n");
strcat( (char *) pSqlStmt, " TYPE mgr_cur IS REF CURSOR;\n\n");
strcat( (char *) pSqlStmt, " PROCEDURE EmpCurs (Ename IN OUT ename_cur,");
strcat( (char *) pSqlStmt, "Mgr IN OUT mgr_cur,pjob IN VARCHAR2);\n\n");
strcat( (char *) pSqlStmt, "END;\n");
rc = SQLExecDirect(hStmt, pSqlStmt, strlen((char *)pSqlStmt));
if (rc != SQL_SUCCESS)
{
  DisplayError(SQL_HANDLE_STMT, hStmt, "SQLExecDirect");
}
/*
 * Create the Package Body
 */
strcpy( (char *) pSqlStmt, "CREATE PACKAGE BODY ODBCRefCur AS\n");
strcat( (char *) pSqlStmt, " PROCEDURE EmpCurs (Ename IN OUT ename_cur,");
strcat( (char *) pSqlStmt, "Mgr IN OUT mgr_cur, pjob IN VARCHAR2)\n AS\n  BEGIN\n");
strcat( (char *) pSqlStmt, " IF NOT Ename%ISOPEN\n THEN\n");
strcat( (char *) pSqlStmt, " OPEN Ename for SELECT ename from emp;\n");
strcat( (char *) pSqlStmt, " END IF;\n\n");
strcat( (char *) pSqlStmt, " IF NOT Mgr%ISOPEN\n THEN\n");
strcat( (char *) pSqlStmt, " OPEN Mgr for SELECT mgr from emp where job = pjob;\n");
strcat( (char *) pSqlStmt, " END IF;\n");
strcat( (char *) pSqlStmt, " END;\n");
strcat( (char *) pSqlStmt, "END;\n");
rc = SQLExecDirect(hStmt, pSqlStmt, strlen((char *)pSqlStmt));
if (rc != SQL_SUCCESS)
{
  DisplayError(SQL_HANDLE_STMT, hStmt, "SQLExecDirect");
}
/*
 * Bind the Parameter
 */
rc = SQLBindParameter(hStmt,1,SQL_PARAM_INPUT,SQL_C_CHAR,SQL_CHAR,JOB_LEN,0,pSalesMan,0,&sqlnts);
/*
 * Call the Store Procedure which executes the Result Sets
 */
strcpy( (char *) pSqlStmt, "{CALL ODBCRefCur.EmpCurs(?)}");
rc = SQLExecDirect(hStmt, pSqlStmt, strlen((char *)pSqlStmt));
if (rc != SQL_SUCCESS)
{
  DisplayError(SQL_HANDLE_STMT, hStmt, "SQLExecDirect");
}
/*
 * Bind the Data
 */
rc = SQLBindCol( hStmt,1,SQL_C_CHAR,Data,sizeof(Data),&DataLen);
if (rc != SQL_SUCCESS)
{
  DisplayError(SQL_HANDLE_STMT, hStmt, "SQLBindCol");
}
/*
 * Get the data for Result Set 1
 */
printf( "\nEmployee Names\n\n");
while ( rc == SQL_SUCCESS )
{
  rc = SQLFetch( hStmt );
  if ( rc == SQL_SUCCESS )
  {
    printf("%s\n", Data);
  }
  else
  {
    if (rc != SQL_NO_DATA)
    {
      DisplayError(SQL_HANDLE_STMT, hStmt, "SQLFetch");
    }
  }
}
printf( "\nFirst Result Set - Hit Return to Continue\n");
charptr = gets ((char *)error);
/*
 * Get the Next Result Set
 */
rc = SQLMoreResults( hStmt );
if (rc != SQL_SUCCESS)
{
  DisplayError(SQL_HANDLE_STMT, hStmt, "SQLMoreResults");
}
/*
 * Get the data for Result Set 2
 */
printf( "\nManagers\n\n");
while ( rc == SQL_SUCCESS )
{
  rc = SQLFetch( hStmt );
  if ( rc == SQL_SUCCESS )
  {
    printf("%s\n", Data);
  }
  else
  {
    if (rc != SQL_NO_DATA)
    {
    DisplayError(SQL_HANDLE_STMT, hStmt, "SQLFetch");
    }
  }
}
printf( "\nSecond Result Set - Hit Return to Continue\n");
charptr = gets ((char *)error);
/*
 * Should Be No More Results Sets
 */
rc = SQLMoreResults( hStmt );
if (rc != SQL_NO_DATA)
{
  DisplayError(SQL_HANDLE_STMT, hStmt, "SQLMoreResults");
}
/*
 * Drop the Package
 */
strcpy( (char *) pSqlStmt, "DROP PACKAGE ODBCRefCur");
rc = SQLExecDirect(hStmt, pSqlStmt, strlen((char *)pSqlStmt));
/*
 * Free handles close connections to the database
 */
SQLFreeHandle( SQL_HANDLE_STMT, hStmt );
SQLDisconnect( hDbc );
SQLFreeHandle( SQL_HANDLE_DBC, hDbc );
SQLFreeHandle( SQL_HANDLE_ENV, hEnv );
printf( "\nAll Done - Hit Return to Exit\n");
charptr = gets ((char *)error);
return(0);
}
/*
 * Display Error Messages
 */
void DisplayError( SWORD HandleType, SQLHANDLE hHandle, char *Module )
{
SQLCHAR MessageText[255];
SQLCHAR SQLState[80];
SQLRETURN rc=SQL_SUCCESS;
long NativeError;
SWORD RetLen;
SQLCHAR error[25];
char *charptr;
rc =
SQLGetDiagRec(HandleType,hHandle,1,SQLState,&NativeError,MessageText,255,&RetLen);
printf( "Failure Calling %s\n", Module );
if (rc == SQL_SUCCESS || rc == SQL_SUCCESS_WITH_INFO)
{
  printf( "\t\t\t State: %s\n", SQLState);
  printf( "\t\t\t Native Error: %d\n", NativeError );
  printf( "\t\t\t Error Message: %s\n", MessageText );
}
printf( "\nHit Return to Exit\n");
charptr = gets ((char *)error);
exit(1);
}

B.10 Enabling EXEC Syntax

If the syntax of the SQL Server EXEC statement can be readily translated to an equivalent Oracle procedure call without requiring any change to it, then Oracle ODBC Driver can translate it if you enable this option.

The complete name of a SQL Server procedure consists of up to four identifiers:

• Server name

• Database name

• Owner name

• Procedure name

The format for the name is:

[[[server.][database].][owner_name].]procedure_name

During the migration of Microsoft SQL Server database to Oracle Database, the definition of each SQL Server procedure or function is converted to its equivalent Oracle Database syntax and is defined in a schema in Oracle Database. Migrated procedures are often reorganized (and created in schemas) in one of the following ways:

• All procedures are migrated to one schema (the default option).

• All procedures defined in one SQL Server database are migrated to the schema named with that database name.

• All procedures owned by one user are migrated to the schema named with that user's name.

To support these three ways of organizing migrated procedures, you can specify one of these schema name options for translating procedure names. Object names in the translated Oracle procedure call are not case-sensitive.

B.11 Supported Functionality

This sections provides information about the functionality supported by Oracle ODBC Driver. It contains the following sections:

• API Conformance

• Implementation of ODBC API Functions

• Implementation of the ODBC SQL Syntax

• Implementation of Data Types

"BAR"
"BARX"
"XBAR"
"XBARX"
"SQLPROCTEST.BAR" 
"SQLPROCTEST.BARX" 
"SQLPROCTEST.XBAR" 
"SQLPROCTEST.XBARX" 

BAR 
BARX 
XBAR 
XBARX 

SQLPROCTEST.BAR
SQLPROCTEST.BARX 
SQLPROCTEST.XBAR 
SQLPROCTEST.XBARX 

BAR
XBAR

SQLPROCTEST.BAR
SQLPROCTEST.XBAR 

nothing (0 rows)

B.12 Unicode Support

This section provide information about Unicode support. It contains the following topics:

• Unicode Support Within the ODBC Environment

• Unicode Support in ODBC API

• SQLGetData Performance

• Unicode Samples

HENV         envHnd;
HDBC         conHnd;
HSTMT        stmtHnd;
RETCODE      rc;

rc  = SQL_SUCCESS;

// ENV is allocated
rc = SQLAllocEnv(&envHnd);
// Connection Handle is allocated
rc = SQLAllocConnect(envHnd, &conHnd);
rc = SQLConnect(conHnd, _T("stpc19"), SQL_NTS, _T("scott"), SQL_NTS, _T("tiger"), SQL_NTS);
.
.
.
if (conHnd)
  SQLFreeConnect(conHnd);
if (envHnd)
  SQLFreeEnv(envHnd);

/*
** Execute SQL, bind columns, and Fetch.
** Procedure:
**
**   SQLExecDirect
**   SQLBindCol
**   SQLFetch
** 
*/
static SQLTCHAR *sqlStmt = _T("SELECT ename, job FROM emp");
SQLTCHAR   ename[50];
SQLTCHAR     job[50];
SQLINTEGER enamelen, joblen;
 
_tprintf(_T("Retrieve ENAME and JOB using SQLBindCol 1.../n[%s]/n"), sqlStmt);
 
// Step 1: Prepare and Execute
rc = SQLExecDirect(stmtHnd, sqlStmt, SQL_NTS); // select
checkSQLErr(envHnd, conHnd, stmtHnd, rc);
 
// Step 2: Bind Columns
rc = SQLBindCol(stmtHnd,
                1,
                SQL_C_TCHAR,
                ename,
                sizeof(ename),
                &enamelen);
checkSQLErr(envHnd, conHnd, stmtHnd, rc);
 
rc = SQLBindCol(stmtHnd,
                2,
                SQL_C_TCHAR,
                job,
                sizeof(job),
                &joblen);
checkSQLErr(envHnd, conHnd, stmtHnd, rc);
 
do 
{
  // Step 3: Fetch Data
  rc = SQLFetch(stmtHnd);
  if (rc == SQL_NO_DATA)
    break;
  checkSQLErr(envHnd, conHnd, stmtHnd, rc);
  _tprintf(_T("ENAME = %s, JOB = %s/n"), ename, job);
} while (1);
_tprintf(_T("Finished Retrieval/n/n"));

/*
** Execute SQL, bind columns, and Fetch.
** Procedure:
**
**   SQLExecDirect
**   SQLFetch
**   SQLGetData
*/
static SQLTCHAR *sqlStmt = _T("SELECT ename,job FROM emp"); // same as Case 1.
SQLTCHAR         ename[50];
SQLTCHAR         job[50];
 
_tprintf(_T("Retrieve ENAME and JOB using SQLGetData.../n[%s]/n"), sqlStmt);
if (rc != SQL_SUCCESS)
{
  _tprintf(_T("Failed to allocate STMT/n"));
  goto exit2;
}
 
// Step 1: Prepare and Execute
rc = SQLExecDirect(stmtHnd, sqlStmt, SQL_NTS); // select
checkSQLErr(envHnd, conHnd, stmtHnd, rc);
 
do 
{
 
  // Step 2: Fetch
  rc = SQLFetch(stmtHnd);
  if (rc == SQL_NO_DATA)
    break;
  checkSQLErr(envHnd, conHnd, stmtHnd, rc);
 
  // Step 3: GetData
  rc = SQLGetData(stmtHnd, 
    1,
    SQL_C_TCHAR,
    (SQLPOINTER)ename,
    sizeof(ename), 
    NULL);
  checkSQLErr(envHnd, conHnd, stmtHnd, rc);
  rc = SQLGetData(stmtHnd, 
    2,
    SQL_C_TCHAR, 
    (SQLPOINTER)job,
    sizeof(job), 
    NULL);
  checkSQLErr(envHnd, conHnd, stmtHnd, rc);
  _tprintf(_T("ENAME = %s, JOB = %s/n"), ename, job);
} while (1);
_tprintf(_T("Finished Retrieval/n/n"));

/*
** Execute SQL, bind columns, and Fetch.
** Procedure:
**
**   SQLPrepare
**   SQLBindParameter
**   SQLExecute
*/
static SQLTCHAR *sqlStmt = _T("INSERT INTO emp(empno,ename,job) VALUES(?,?,?)");
static SQLTCHAR *empno   = _T("9876");      // Emp No
static SQLTCHAR *ename   = _T("ORACLE");    // Name
static SQLTCHAR *job     = _T("PRESIDENT"); // Job
 
_tprintf(_T("Insert User ORACLE using SQLBindParameter.../n[%s]/n"), sqlStmt);
 
// Step 1: Prepare
rc = SQLPrepare(stmtHnd, sqlStmt, SQL_NTS); // select
checkSQLErr(envHnd, conHnd, stmtHnd, rc);
 
// Step 2: Bind Parameter
rc = SQLBindParameter(stmtHnd, 
                      1, 
                      SQL_PARAM_INPUT,
                      SQL_C_TCHAR,
                      SQL_DECIMAL,
                      4,               // 4 digit
                      0,
                      (SQLPOINTER)empno,
                      0,
                      NULL);
checkSQLErr(envHnd, conHnd, stmtHnd, rc);
 
rc = SQLBindParameter(stmtHnd, 
                      2, 
                      SQL_PARAM_INPUT,
                      SQL_C_TCHAR,
                      SQL_CHAR,
                      lstrlen(ename)*sizeof(TCHAR),
                      0,
                      (SQLPOINTER)ename,
                      lstrlen(ename)*sizeof(TCHAR),
                      NULL);
checkSQLErr(envHnd, conHnd, stmtHnd, rc);
 
rc = SQLBindParameter(stmtHnd, 
                      3, 
                      SQL_PARAM_INPUT,
                      SQL_C_TCHAR,
                      SQL_CHAR,
                      lstrlen(job)*sizeof(TCHAR),
                      0,
                      (SQLPOINTER)job,
                      lstrlen(job)*sizeof(TCHAR),
                      NULL);
checkSQLErr(envHnd, conHnd, stmtHnd, rc);
 
// Step 3: Execute
rc = SQLExecute(stmtHnd);
checkSQLErr(envHnd, conHnd, stmtHnd, rc);

/*
** Execute SQL, bind columns, and Fetch.
** Procedure:
**
**   SQLPrepare
**   SQLBindParameter
**   SQLExecute
**   SQLParamData
**   SQLPutData
**
**   SQLExecDirect
**   SQLFetch
**   SQLGetData
*/
static SQLTCHAR *sqlStmt1  = _T("INSERT INTO clobtbl(clob1) VALUES(?)");
static SQLTCHAR *sqlStmt2  = _T("SELECT clob1 FROM clobtbl");
SQLTCHAR         clobdata[1001];
SQLTCHAR         resultdata[1001];
SQLINTEGER       ind = SQL_DATA_AT_EXEC;
SQLTCHAR        *bufp;
int              clobdatalen, chunksize, dtsize, retchklen;
 
_tprintf(_T("Insert CLOB1 using SQLPutData.../n[%s]/n"), sqlStmt1);
 
// Set CLOB Data
{
  int i;
  SQLTCHAR ch;
  for (i=0, ch=_T('A'); i< sizeof(clobdata)/sizeof(SQLTCHAR); ++i, ++ch)
  {
    if (ch > _T('Z'))
      ch = _T('A');
    clobdata[i] = ch;
  }
  clobdata[sizeof(clobdata)/sizeof(SQLTCHAR)-1] = _T('/0');
}
clobdatalen = lstrlen(clobdata);  // length of characters
chunksize   = clobdatalen / 7;    // 7 times to put

// Step 1: Prepare
rc = SQLPrepare(stmtHnd, sqlStmt1, SQL_NTS);
checkSQLErr(envHnd, conHnd, stmtHnd, rc); 
// Step 2: Bind Parameter with SQL_DATA_AT_EXEC
rc = SQLBindParameter(stmtHnd, 
                      1, 
                      SQL_PARAM_INPUT,
                      SQL_C_TCHAR,
                      SQL_LONGVARCHAR,
                      clobdatalen*sizeof(TCHAR),
                      0,
                      (SQLPOINTER)clobdata,
                      clobdatalen*sizeof(TCHAR),
                      &ind);
checkSQLErr(envHnd, conHnd, stmtHnd, rc); 
// Step 3: Execute
rc = SQLExecute(stmtHnd);
checkSQLErr(envHnd, conHnd, stmtHnd, rc);
 
// Step 4: ParamData (initiation)
rc = SQLParamData(stmtHnd, (SQLPOINTER*)&bufp); // set value
checkSQLErr(envHnd, conHnd, stmtHnd, rc);
 
for (dtsize=0, bufp = clobdata;
     dtsize < clobdatalen;
     dtsize += chunksize, bufp += chunksize)
{
  int len;
  if (dtsize+chunksize<clobdatalen)
    len = chunksize;
  else
    len = clobdatalen-dtsize;
 
  // Step 5: PutData
  rc = SQLPutData(stmtHnd, (SQLPOINTER)bufp, len*sizeof(TCHAR));
  checkSQLErr(envHnd, conHnd, stmtHnd, rc);
}
 
// Step 6: ParamData (temination)
rc = SQLParamData(stmtHnd, (SQLPOINTER*)&bufp);
checkSQLErr(envHnd, conHnd, stmtHnd, rc);
 
rc = SQLFreeStmt(stmtHnd, SQL_CLOSE);
_tprintf(_T("Finished Update/n/n"));
rc = SQLAllocStmt(conHnd, &stmtHnd);
if (rc != SQL_SUCCESS)
{
  _tprintf(_T("Failed to allocate STMT/n"));
  goto exit2;
}
 
// Clear Result Data
memset(resultdata, 0, sizeof(resultdata));
chunksize   = clobdatalen / 15;   // 15 times to put
 
// Step 1: Prepare
rc = SQLExecDirect(stmtHnd, sqlStmt2, SQL_NTS); // select
checkSQLErr(envHnd, conHnd, stmtHnd, rc);
 
// Step 2: Fetch
rc = SQLFetch(stmtHnd);
checkSQLErr(envHnd, conHnd, stmtHnd, rc); 
for(dtsize=0, bufp = resultdata;
    dtsize < sizeof(resultdata)/sizeof(TCHAR) && rc != SQL_NO_DATA;
    dtsize += chunksize-1, bufp += chunksize-1)
{
  int len; // len should contain the space for NULL termination
  if (dtsize+chunksize<sizeof(resultdata)/sizeof(TCHAR))
    len = chunksize;
  else
    len = sizeof(resultdata)/sizeof(TCHAR)-dtsize;
 
  // Step 3: GetData
  rc = SQLGetData(stmtHnd, 
    1,
    SQL_C_TCHAR,
    (SQLPOINTER)bufp,
    len*sizeof(TCHAR), 
    &retchklen);
}
if (!_tcscmp(resultdata, clobdata))
{
  _tprintf(_T("Succeeded!!/n/n"));
}
else
{
  _tprintf(_T("Failed!!/n/n"));
}

B.13 Performance and Tuning

This section contains the following topics:

• General ODBC Programming Guidelines

• Data Source Configuration Options

• DATE and TIMESTAMP Data Types

SELECT * FROM EMP WHERE HIREDATE = ?

SELECT * FROM EMP WHERE TO_TIMESTAMP(HIREDATE) = ?

B.14 Error Messages

When an error occurs, Oracle ODBC Driver returns the native error number, the SQLSTATE (an ODBC error code), and an error message. The driver derives this information both from errors detected by the driver and errors returned by Oracle Database.

Native Error

For errors that occur in the data source, Oracle ODBC Driver returns the native error returned to it by Oracle Database. When Oracle ODBC Driver or the Driver Manager detects an error, Oracle ODBC Driver returns a native error of zero.

SQLSTATE

For errors that occur in the data source, Oracle ODBC Driver maps the returned native error to the appropriate SQLSTATE. When Oracle ODBC Driver or the Driver Manager detects an error, it generates the appropriate SQLSTATE.

Error Message

For errors that occur in the data source, Oracle ODBC Driver returns an error message based on the message returned by Oracle Database. For errors that occur in Oracle ODBC Driver or the Driver Manager, Oracle ODBC Driver returns an error message based on the text associated with the SQLSTATE.

Error messages have the following format:

[vendor] [ODBC-component] [data-source] error-message

The prefixes in brackets ([ ]) identify the source of the error. The following table shows the values of these prefixes returned by Oracle ODBC Driver. When the error occurs in the data source, the vendor and ODBC-component prefixes identify the vendor and name of the ODBC component that received the error from the data source.

For example, if the error message does not contain the Ora prefix shown in the following format, then error is an Oracle ODBC Driver error and should be self-explanatory.

[Oracle][ODBC]Error message text here

If the error message contains the Ora prefix shown in the following format, then it is not an Oracle ODBC Driver error.

[Oracle][ODBC][Ora]Error message text here

If the error message text starts with the ORA- prefix, then you can obtain more information about the error in Oracle Database documentation.