Help Center/ GaussDB/ M-Compatibility Developer Guide(Centralized)/ SQL Reference/ SQL Syntax/ SQL Statements/ D/ DEALLOCATE
Updated on 2025-10-23 GMT+08:00
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DEALLOCATE

Description

Deallocates a previously prepared statement.

Precautions

If you do not explicitly deallocate a prepared statement, it is deallocated when the session ends.

Syntax

{DEALLOCATE | DROP}  PREPARE name;

Parameters

name

Specifies the name of the prepared statement to be deallocated.

Examples

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-- Create three prepared statements q1, q2, and q3, delete q1, and then delete all prepared statements.
m_db=# SELECT name, statement, parameter_types FROM pg_prepared_statements;
 name | statement | parameter_types 
------+-----------+-----------------
(0 rows)

m_db=# PREPARE q1 from  'SELECT 1 AS a';
PREPARE
m_db=# PREPARE q2 from 'SELECT 1 AS a';
PREPARE
m_db=# PREPARE q3 from 'SELECT 1 AS a';
PREPARE
m_db=# SELECT name, statement, parameter_types FROM pg_prepared_statements;
 name |          statement           | parameter_types 
------+------------------------------+-----------------
 q1   | PREPARE q1 AS SELECT 1 AS a; | {}
 q3   | PREPARE q3 AS SELECT 1 AS a; | {}
 q2   | PREPARE q2 AS SELECT 1 AS a; | {}
(3 rows)

m_db=# DEALLOCATE PREPARE q1;
DEALLOCATE
m_db=# SELECT name, statement, parameter_types FROM pg_prepared_statements;
 name |          statement           | parameter_types 
------+------------------------------+-----------------
 q3   | PREPARE q3 AS SELECT 1 AS a; | {}
 q2   | PREPARE q2 AS SELECT 1 AS a; | {}
(2 rows)
Parent topic: D