Collection Method Invocation

A collection method is a PL/SQL subprogram that either returns information about a collection or operates on a collection.

Topics

• Syntax

• Semantics

• Examples

• Related Topics

Syntax

collection_method_call ::=

Description of the illustration collection_method_call.gif

Semantics

collection

Name of the collection whose method you are invoking.

COUNT

Function that returns the number of elements in the collection, explained in "COUNT Collection Method".

DELETE

Procedure that deletes elements from the collection, explained in "DELETE Collection Method".

Restriction on DELETE If collection is a varray, you cannot specify indexes with DELETE.

index

Numeric expression whose data type either is PLS_INTEGER or can be implicitly converted to PLS_INTEGER (for information about the latter, see "Predefined PLS_INTEGER Subtypes").

EXISTS

Function that returns TRUE if the indexth element of the collection exists and FALSE otherwise, explained in "EXISTS Collection Method".

Restriction on EXISTS You cannot use EXISTS if collection is an associative array.

EXTEND

Procedure that adds elements to the end of the collection, explained in "EXTEND Collection Method".

Restriction on EXTEND You cannot use EXTEND if collection is an associative array.

FIRST

Function that returns the first index in the collection, explained in "FIRST and LAST Collection Methods".

LAST

Function that returns the last index in the collection, explained in "FIRST and LAST Collection Methods".

LIMIT

Function that returns the maximum number of elements that the collection can have. If the collection has no maximum size, then LIMIT returns NULL. For an example, see "LIMIT Collection Method".

NEXT

Function that returns the index of the succeeding existing element of the collection, if one exists. Otherwise, NEXT returns NULL. For more information, see "PRIOR and NEXT Collection Methods".

PRIOR

Function that returns the index of the preceding existing element of the collection, if one exists. Otherwise, NEXT returns NULL. For more information, see "PRIOR and NEXT Collection Methods".

TRIM

Procedure that deletes elements from the end of a collection, explained in "TRIM Collection Method".

Restriction on TRIM You cannot use TRIM if collection is an associative array.

number

Number of elements to delete from the end of a collection. Default: one.

Examples

• Example 5-17, "DELETE Method with Nested Table"

• Example 5-18, "DELETE Method with Associative Array Indexed by String"

• Example 5-19, "TRIM Method with Nested Table"

• Example 5-20, "EXTEND Method with Nested Table"

• Example 5-21, "EXISTS Method with Nested Table"

• Example 5-22, "FIRST and LAST Values for Associative Array Indexed by PLS_INTEGER"

• Example 5-23, "FIRST and LAST Values for Associative Array Indexed by String"

• Example 5-24, "Printing Varray with FIRST and LAST in FOR LOOP"

• Example 5-25, "Printing Nested Table with FIRST and LAST in FOR LOOP"

• Example 5-26, "COUNT and LAST Values for Varray"

• Example 5-27, "COUNT and LAST Values for Nested Table"

• Example 5-28, "LIMIT and COUNT Values for Different Collection Types"

• Example 5-29, "PRIOR and NEXT Methods"

• Example 5-30, "Printing Elements of Sparse Nested Table"

Related Topics

In this chapter:

• "Collection Variable Declaration"

In other chapters:

• "Collection Methods"