How to use stored procedures and triggers in MySQL?

In MySQL, you can use stored procedures and triggers to achieve specific functions. Here, we will introduce how to create and use stored procedures and triggers.

1. Stored procedure:

A stored procedure is a collection of SQL statements designed to perform a specific task, which can be stored in a database and executed when needed. Using stored procedures can simplify complex operations and improve database performance.

The syntax for creating a stored procedure is as follows:

CREATE PROCEDURE procedure_name()
BEGIN
    -- SQL statements
END;

The syntax for calling a stored procedure is as follows:

CALL procedure_name();

1. trigger:

A trigger is a special type of stored procedure that automatically executes in a database table when specific events occur, such as insert, update, or delete operations.

The syntax for creating triggers is as follows:

CREATE TRIGGER trigger_name
BEFORE INSERT OR UPDATE OR DELETE ON table_name
FOR EACH ROW
BEGIN
    -- SQL statements
END;

In the syntax above, BEFORE indicates the trigger will execute before an event, AFTER indicates the trigger will execute after an event, INSERT, UPDATE, and DELETE indicate the types of events the trigger listens to, and FOR EACH ROW indicates the trigger will execute for each individual row.

It is important to note that creating stored procedures and triggers requires specific permissions, typically CREATE PROCEDURE and CREATE TRIGGER permissions. When using stored procedures and triggers, it is important to design and use them properly to avoid negatively impacting the performance of the database.