Mysql stored procedures and functions are introduced differently

  • 2020-06-12 10:47:45
  • OfStack

A stored procedure is a collection of user-defined series 1 sql statements that involve tasks involving specific tables or other objects and can be invoked by the user, while a function is usually a database defined method that takes parameters and returns a value of some type and does not involve a specific user table.

There are several differences between stored procedures and functions:

1) Generally speaking, the functions of stored procedures are more complex, while the functions of functions are more targeted. Stored procedures, powerful, can be performed including table modification 1 series of database operations; User-defined functions cannot be used to perform a set of operations that modify the state of the global database.

2) For stored procedures, parameters such as recordsets can be returned, while functions can only return values or table objects. A function can only return 1 variable; A stored procedure can return more than one. The parameters of the stored procedure can be of IN,OUT and INOUT3 types, while the function can only have IN class ~~ When the stored procedure is declared, the return type is not required, while the function declaration needs to describe the return type, and the function body must contain a valid RETURN statement.

3) Stored procedures. Non-deterministic functions can be used and are not allowed to be built into the body of user-defined functions.

4) Stored procedure 1 is typically executed as a separate part (EXECUTE statement), while the function can be called as part of the query (SELECT call). Since the function can return a table object, it can be placed after the FROM keyword in the query. Stored procedures are not available in SQL statements, but functions are.

Related articles: