Lu, Huayi e6fa411af0 DWS DEV 830.201 version

Reviewed-by: Pruthi, Vineet <vineet.pruthi@t-systems.com>
Co-authored-by: Lu, Huayi <luhuayi@huawei.com>
Co-committed-by: Lu, Huayi <luhuayi@huawei.com>

2024-05-16 07:24:04 +00:00

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ALTER TRIGGER

Function

ALTER TRIGGER modifies the definition of a trigger.

Precautions

Only the owner of a table where a trigger is created and system administrators can run the ALTER TRIGGER statement.

Syntax

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ALTER TRIGGER trigger_name ON table_name RENAME TO new_name;

Parameter Description

trigger_name
Specifies the name of the trigger to be modified.

Value range: an existing trigger
table_name
Specifies the name of the table where the trigger to be modified is located.

Value range: an existing table having a trigger
new_name
Specifies the new trigger name.

Value range: a string that complies with the identifier naming convention. A value contains a maximum of 63 characters and cannot be the same as other triggers on the same table.

Example

Create a source table and a trigger table:

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DROP TABLE IF EXISTS test_trigger_src_tbl;
DROP TABLE IF EXISTS test_trigger_des_tbl;

CREATE TABLE test_trigger_src_tbl(id1 INT, id2 INT, id3 INT);
CREATE TABLE test_trigger_des_tbl(id1 INT, id2 INT, id3 INT);

Create the trigger function tri_insert_func():

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DROP FUNCTION IF EXISTS tri_insert_func;
CREATE OR REPLACE FUNCTION tri_insert_func() RETURNS TRIGGER AS
           $$
           DECLARE
           BEGIN
                   INSERT INTO test_trigger_des_tbl VALUES(NEW.id1, NEW.id2, NEW.id3);
                   RETURN NEW;
           END
           $$ LANGUAGE PLPGSQL;

Create an INSERT trigger:

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CREATE TRIGGER insert_trigger
           BEFORE INSERT ON test_trigger_src_tbl
           FOR EACH ROW
           EXECUTE PROCEDURE tri_insert_func();

Modified the trigger delete_trigger.

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ALTER TRIGGER insert_trigger ON test_trigger_src_tbl RENAME TO insert_trigger_renamed;

Disable the trigger insert_trigger.

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ALTER TABLE test_trigger_src_tbl DISABLE TRIGGER insert_trigger_renamed;  

Disable all triggers on the test_trigger_src_tbl table.

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ALTER TABLE test_trigger_src_tbl DISABLE TRIGGER ALL; 

Helpful Links

CREATE TRIGGER, DROP TRIGGER, ALTER TABLE

Parent topic: DDL Syntax

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