How to delete triggers for mysql databases
Editor to share with you how to delete mysql database triggers, I hope you will learn a lot after reading this article, let's discuss it together!
In mysql, you can use the "DROP TRIGGER" statement to delete a defined trigger in the syntax format "DROP TRIGGER [IF EXISTS] [database name] trigger name"; when you delete a table, the trigger on that table is also automatically deleted.
Delete trigger
Use the DROP TRIGGER statement to delete triggers that are already defined in MySQL.
The syntax format is as follows:
DROP TRIGGER [IF EXISTS] [database name]
The syntax is as follows:
1) trigger name
The name of the trigger to delete.
2) Database name
Optional. Specifies the name of the database where the trigger is located. If not specified, it is the current default database.
3) permissions
SUPER permission is required to execute the DROP TRIGGER statement.
4) IF EXISTS
Optional. Avoid deleting triggers without triggers.
Note: when you delete a table, the trigger on that table is also automatically deleted. In addition, triggers cannot be updated or overwritten, and in order to modify a trigger, you must delete it and then recreate it.
[example] Delete the double_salary trigger, and enter the SQL statement and execution process as shown below.
Mysql > DROP TRIGGER double_salary;Query OK, 0 rows affected (0.03 sec)
When you delete the double_salary trigger and insert the record into the data table tb_emp6 again, the data in the data table tb_emp7 no longer changes, as shown below.
Mysql > INSERT INTO tb_emp6-> VALUES; Query OK, 1 row affected (0.09 sec) mysql > SELECT * FROM tb_emp6 +-A | 1 | 1000 | 2 | B | 1 | 1000 | 3 | C | 1 | 200 | +-+-- -+-+ 3 rows in set (0.00 sec) mysql > SELECT * FROM tb_emp7 +-+ | id | name | deptId | salary | +-+ | 1 | A | 1 | 2000 | | 2 | B | 1 | 1000 | +-+- -- + 2 rows in set (0.00 sec) finished reading this article I believe you have a certain understanding of how to delete mysql database triggers, want to know more about it, welcome to follow the industry information channel, thank you for reading!
