1, to improve security. Mysql triggers can give users some permissions to operate the database according to the value of the database. Be able to limit the user's operation based on time, such as not agreeing to change the database data after work and holidays.

2. Audit. Mysql triggers can track users' operations on the database. Audit the statements of users who operate the database, and write the user's updates to the database into the audit table.

3.mysql triggers implement complex data integrity rules and nonstandard data integrity checks and constraints. Triggers can create restrictions that are more complex than rules. Unlike rules, triggers can refer to columns or database objects. For example, a trigger can be backed off to provide a variable default value, no matter what attempts to eat futures beyond its own margin.

4. Implement the integrity rules related to complex nonstandard databases. Triggers can update related tables in the database in a serial manner.