Object types are defined using PL/SQL. Therefore, this section provides some general information but refers to Oracle Database PL/SQL Language Reference for details of syntax and semantics.
TYPE statement to create the specification of an object type, a SQLJ object type, a named varying array (varray), a nested table type, or an incomplete object type. You create object types with the
TYPE and the
BODY statements. The
TYPE statement specifies the name of the object type, its attributes, methods, and other properties. The
BODY statement contains the code for the methods that implement the type.
If you create an object type for which the type specification declares only attributes but no methods, then you need not specify a type body.
If you create a SQLJ object type, then you cannot specify a type body. The implementation of the type is specified as a Java class.
An incomplete type is a type created by a forward type definition. It is called "incomplete" because it has a name but no attributes or methods. It can be referenced by other types, and so can be used to define types that refer to each other. However, you must fully specify the type before you can use it to create a table or an object column or a column of a nested table type.
CREATE TYPE BODY for information on creating the member methods of a type
Oracle Database Object-Relational Developer's Guide for more information about objects, incomplete types, varrays, and nested tables
To create a type in your own schema, you must have the
TYPE system privilege. To create a type in another user's schema, you must have the
TYPE system privilege. You can acquire these privileges explicitly or be granted them through a role.
To create a subtype, you must have the
TYPE system privilege or the
UNDER object privilege on the supertype.
The owner of the type must be explicitly granted the
EXECUTE object privilege in order to access all other types referenced within the definition of the type, or the type owner must be granted the
TYPE system privilege. The owner cannot obtain these privileges through roles.
If the type owner intends to grant other users access to the type, then the owner must be granted the
EXECUTE object privilege on the referenced types with the
OPTION or the
TYPE system privilege with the
OPTION. Otherwise, the type owner has insufficient privileges to grant access on the type to other users.
User-Defined Datatypes Declared as Non-Persistable Datatypes
You can specify a user-defined datatype as non-persistable when creating the datatype. Instances of non-persistable types cannot persist on disk. Perisistable data types include the following:
ANSI-supported data types, for example
Oracle built-in data types, for example
Oracle-supplied data types, for example
Rules For SQL User-Defined Data Types
A persistable type cannot have attributes or elements of non-persistable types.
A non-persistable type can have attributes or elements of both persistable and non-persistable types.
A sub-type must inherit the persistence property from its super type.
REFtype is persistable and can hold references only to objects of persistable types.
You cannot persist instances of non-persistable types on disk. If you create a table with a type that has been declared as non-persistable, the
CREATE TABLEstatement will fail. The following operations will likewise fail:
Create or alter a relational table with columns of non-persistable types.
Create an object table with columns of non-persistable types.
Store instances of non-persistable types in an
ANYDATAinstance which is persisted on disk.
Types are defined using PL/SQL. Therefore, the syntax diagram in this book shows only the SQL keywords. Refer to Oracle Database PL/SQL Language Reference for the PL/SQL syntax, semantics, and examples.
plsql_type_source: See Oracle Database PL/SQL Language Reference.)
Users previously granted privileges on the re-created object type can use and reference the object type without being granted privileges again.
If any function-based indexes depend on the type, then Oracle Database marks the indexes
[ EDITIONABLE | NONEDITIONABLE ]
Use these clauses to specify whether the type is an editioned or noneditioned object if editioning is enabled for the schema object type
schema.The default is
EDITIONABLE. For information about editioned and noneditioned objects, see Oracle Database Development Guide.
See Oracle Database PL/SQL Language Reference for the syntax and semantics of the