What is the usage of a mysql procedure?

MySQL stored procedures are a collection of SQL statements and logical control structures such as conditionals and loops designed to perform specific tasks. They can be called, executed, accept parameters, and return results. Stored procedures are commonly used for:

1. Encapsulating complex business logic: Stored procedures can encapsulate complex business logic into a reusable unit, enhancing code reusability and maintainability.
2. Improve performance: Stored procedures are precompiled and stored in the database, reducing the overhead of executing SQL statements each time and enhancing query execution efficiency.
3. Security control: Stored procedures can be used to restrict user access to the database, only allowing database access through stored procedures, which enhances data security.
4. Streamlining application development: By calling stored procedures, applications can directly execute the functionality of stored procedures without needing to write complex SQL statements, thus simplifying the development process of the application.
5. Transactions: Stored procedures can encapsulate multiple SQL statements into one transaction, achieving data consistency and integrity.

In order to utilize MySQL stored procedures, the first step is to create the procedure using the CREATE PROCEDURE statement to define the name, parameters, and SQL commands to execute. Afterwards, you can call the procedure using the CALL statement, passing any necessary parameters. Stored procedures can be executed in MySQL clients or applications and can transfer data using IN, OUT, and INOUT parameters.