1CREATE DATABASE db1; 2USE db1; 3CREATE TABLE t1 (val INT); 4CREATE TRIGGER IF NOT EXISTS val_sum BEFORE INSERT ON t1 FOR EACH ROW SET @sum = @sum + NEW.val; 5SET @sum=0; 6INSERT INTO t1 VALUES (10), (20), (30); 7SELECT @sum; 8@sum 960 10CREATE TRIGGER IF NOT EXISTS val_sum_new BEFORE INSERT ON t1 FOR EACH ROW SET @sum = @sum + NEW.val; 11CREATE TRIGGER IF NOT EXISTS val_sum AFTER INSERT ON t1 FOR EACH ROW SET @sum = @sum + 1 + NEW.val; 12Warnings: 13Note 1359 Trigger 'db1.val_sum' already exists 14CREATE OR REPLACE TRIGGER IF NOT EXISTS val_sum BEFORE INSERT ON t1 FOR EACH ROW SET @sum = @sum + 2 + NEW.val; 15ERROR HY000: Incorrect usage of OR REPLACE and IF NOT EXISTS 16SELECT ACTION_STATEMENT FROM INFORMATION_SCHEMA.TRIGGERS WHERE TRIGGER_NAME='val_sum'; 17ACTION_STATEMENT 18SET @sum = @sum + NEW.val 19CREATE OR REPLACE TRIGGER val_sum BEFORE INSERT ON t1 FOR EACH ROW SET @sum = @sum + 3 + NEW.val; 20SELECT ACTION_STATEMENT FROM INFORMATION_SCHEMA.TRIGGERS WHERE TRIGGER_NAME='val_sum'; 21ACTION_STATEMENT 22SET @sum = @sum + 3 + NEW.val 23CREATE TRIGGER val_sum BEFORE INSERT ON t1 FOR EACH ROW SET @sum = @sum + 4 + NEW.val; 24ERROR HY000: Trigger 'db1.val_sum' already exists 25SELECT ACTION_STATEMENT FROM INFORMATION_SCHEMA.TRIGGERS WHERE TRIGGER_NAME='val_sum'; 26ACTION_STATEMENT 27SET @sum = @sum + 3 + NEW.val 28# Clearing up 29DROP TRIGGER IF EXISTS val_sum; 30SELECT ACTION_STATEMENT FROM INFORMATION_SCHEMA.TRIGGERS WHERE TRIGGER_NAME='val_sum'; 31ACTION_STATEMENT 32DROP TRIGGER IF EXISTS val_sum; 33Warnings: 34Note 1360 Trigger does not exist 35DROP TABLE t1; 36DROP DATABASE db1; 37