Oracle® Database PL/SQL Language Reference 11g Release 2 (11.2) Part Number E10472-02 |
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The CREATE
TYPE
BODY
defines or implements the member methods defined in the type specification that was created with the "CREATE TYPE Statement".
For each method specified in a type specification for which you did not specify the call_spec,
you must specify a corresponding method body in the type body.
Note:
If you create a SQLJ object type, then specify it as a Java class.Topics:
Prerequisites
Every member declaration in the CREATE
TYPE
specification for an ADT must have a corresponding construct in the CREATE
TYPE
or CREATE
TYPE
BODY
statement.
To create or replace a type body in your own schema, you must have the CREATE
TYPE
or the CREATE
ANY
TYPE
system privilege. To create a type in another user's schema, you must have the CREATE
ANY
TYPE
system privilege. To replace a type in another user's schema, you must have the DROP
ANY
TYPE
system privilege.
Syntax
create_type_body ::=
See:
subprog_decl_in_type ::=
proc_decl_in_type ::=
See:
func_decl_in_type ::=
See:
constructor_declaration ::=
map_order_func_declaration ::=
call_spec ::=
Java_declaration ::=
C_declaration ::=
Semantics
OR REPLACE
Re-creates the type body if it exists, and recompiles it.
Users who were granted privileges on the type body before it was redefined can still access the type body without being regranted the privileges.
You can use this clause to add member subprogram definitions to specifications added with the ALTER
TYPE
... REPLACE
statement.
schema
The name of the schema containing the type body. The default is your own schema.
type_name
The name of an ADT.
subprog_decl_in_type
The type of function or procedure subprogram associated with the type specification.
You must define a corresponding method name and optional parameter list in the type specification for each procedure or function declaration. For functions, you also must specify a return type.
proc_decl_in_type, func_decl_in_type
A procedure or function subprogram declaration.
constructor_declaration
A user-defined constructor subprogram declaration. The RETURN
clause of a constructor function must be RETURN
SELF
AS
RESULT
. This setting indicates that the most specific type of the value returned by the constructor function is the most specific type of the SELF
argument that was passed in to the constructor function.
See Also:
"CREATE TYPE Statement" for a list of restrictions on user-defined functions
"Overloaded Subprograms" for information about overloading subprogram names
Oracle Database Object-Relational Developer's Guide for information about and examples of user-defined constructors
declare_section
Declares items that are local to the procedure or function.
body
Procedure or function statements.
call_spec
The call specification that maps a Java or C method name, parameter types, and return type to their SQL counterparts.
The Java_declaration
string identifies the Java implementation of the method.
See Also:
Oracle Database Java Developer's Guide for an explanation of the parameters and semantics of the Java_declaration
Oracle Database Advanced Application Developer's Guide for information about calling external procedures
map_order_func_declaration
You can declare either one MAP
method or one ORDER
method, regardless of how many MEMBER
or STATIC
methods you declare. If you declare either a MAP
or ORDER
method, then you can compare object instances in SQL.
If you do not declare either method, then you can compare object instances only for equality or inequality. Instances of the same type definition are equal only if each pair of their corresponding attributes is equal.
MAP MEMBER
Declares or implements a MAP
member function that returns the relative position of a given instance in the ordering of all instances of the object. A MAP
method is called implicitly and specifies an ordering of object instances by mapping them to values of a predefined scalar type. PL/SQL uses the ordering to evaluate Boolean expressions and to perform comparisons.
If the argument to the MAP
method is null, then the MAP
method returns null and the method is not invoked.
An type body can contain only one MAP
method, which must be a function. The MAP
function can have no arguments other than the implicit SELF
argument.
ORDER MEMBER
Specifies an ORDER
member function that takes an instance of an object as an explicit argument and the implicit SELF
argument and returns either a negative integer, zero, or a positive integer, indicating that the implicit SELF
argument is less than, equal to, or greater than the explicit argument, respectively.
If either argument to the ORDER
method is null, then the ORDER
method returns null and the method is not invoked.
When instances of the same ADT definition are compared in an ORDER
BY
clause, the database invokes the ORDER
MEMBER
func_decl_in_type
.
An object specification can contain only one ORDER
method, which must be a function having the return type NUMBER
.
func_decl_in_type
A function subprogram declaration. See "CREATE PROCEDURE Statement" and "CREATE FUNCTION Statement" for the full syntax with all possible clauses.
AS EXTERNAL
An alternative way of declaring a C method. This clause is deprecated and is supported for backward compatibility only. Oracle recommends that you use the call_spec
syntax with the C_declaration
.
Examples
Several examples of creating type bodies appear in the Examples section of "CREATE TYPE Statement". For an example of re-creating a type body, see "Adding a Member Function: Example".
Related Topics