DROP TYPE

DROP TYPE

Purpose

Use the DROP TYPE statement to drop the specification and body of an object type, a varray, or nested table type.

See Also:

■DROP TYPE BODY on page 17-18 for information on dropping just the body of an object type

■CREATE TYPE on page 16-3 for information on creating types

Prerequisites

The object type, varray, or nested table type must be in your own schema or you must have the DROP ANY TYPE system privilege.

Syntax

drop_type::=

Semantics

schema

Specify the schema containing the type. If you omit schema, then Oracle assumes the type is in your own schema.

type_name

Specify the name of the object, varray, or nested table type to be dropped. You can drop only types with no type or table dependencies.

If type_name is a supertype, then this statement will fail unless you also specify FORCE. If you specify FORCE, then Oracle invalidates all subtypes depending on this supertype.

SQL Statements: DROP SEQUENCE to ROLLBACK 17-15

DROP TYPE

If type_name is a statistics type, then this statement will fail unless you also specify FORCE. If you specify FORCE, then Oracle first disassociates all objects that are associated with type_name, and then drops type_name.

See Also: ASSOCIATE STATISTICS on page 12-50 and DISASSOCIATE STATISTICS on page 16-64 for more information on statistics types

If type_name is an object type that has been associated with a statistics type, then Oracle first attempts to disassociate type_name from the statistics type and then drop type_name. However, if statistics have been collected using the statistics type, then Oracle will be unable to disassociate type_name from the statistics type, and this statement will fail.

If type_name is an implementation type for an indextype, then the indextype will be marked INVALID.

If type_name has a public synonym defined on it, then Oracle will also drop the synonym.

Unless you specify FORCE, you can drop only object types, nested tables, or varray types that are standalone schema objects with no dependencies. This is the default behavior.

See Also: CREATE INDEXTYPE on page 13-95

FORCE

Specify FORCE to drop the type even if it has dependent database objects. Oracle marks UNUSED all columns dependent on the type to be dropped, and those columns become inaccessible.

Caution: Oracle does not recommend that you specify FORCE to drop types with dependencies. This operation is not recoverable and could cause the data in the dependent tables or columns to become inaccessible. For information about type dependencies, see

Oracle9i Application Developer’s Guide - Fundamentals.

VALIDATE

If you specify VALIDATE when dropping a type, then Oracle checks for stored instances of this type within substitutable columns of any of its supertypes. If no such instances are found, then Oracle completes the drop operation.

17-16 Oracle9i SQL Reference

DROP TYPE

This clause is meaningful only for subtypes. Oracle Corporation recommends the use of this option to safely drop subtypes that do not have any "explicit" type or table dependencies.

Example

Dropping an Object Type: Example The following statement removes object type person_t (created in "Type Hierarchy Example" on page 16-22):

DROP TYPE person_t;

SQL Statements: DROP SEQUENCE to ROLLBACK 17-17

DROP TYPE BODY

DROP TYPE BODY

Purpose

Use the DROP TYPE BODY statement to drop the body of an object type, varray, or nested table type. When you drop a type body, the object type specification still exists, and you can re-create the type body. Prior to re-creating the body, you can still use the object type, although you cannot call the member functions.

See Also:

■DROP TYPE on page 17-15 for information on dropping the specification of an object along with the body

■CREATE TYPE BODY on page 16-25 for more information on type bodies

Prerequisites

The object type body must be in your own schema, and you must have

Syntax drop_type_body::=

Semantics

schema

Specify the schema containing the object type. If you omit schema, then Oracle assumes the object type is in your own schema.

type_name

Specify the name of the object type body to be dropped.

Restriction on Dropping Type Bodies You can drop a type body only if it has no type or table dependencies.

17-18 Oracle9i SQL Reference

DROP TYPE BODY

Example

Dropping an Object Type Body: Example The following statement removes object type body data_typ (created in "Updating a Type Body: Example" on page 16-31):

DROP TYPE BODY data_typ;

SQL Statements: DROP SEQUENCE to ROLLBACK 17-19