![]() Once the function is created, you can view it in MySQL Workbench under the Functions section: The following CREATE FUNCTION statement creates a function that returns the customer level based on credit: DELIMITER $$ĭETERMINISTIC BEGIN DECLARE customerLevel VARCHAR( 20) We will use the customers table in the sample database for the demonstration. Let’s take the example of creating a stored function. Whenever the RETURN statement is reached, the execution of the stored function is terminated immediately. Inside the body section, you need to specify at least one RETURN statement. The RETURN statement returns a value to the calling programs. If you don’t use DETERMINISTIC or NOT DETERMINISTIC, MySQL uses the NOT DETERMINISTIC option by default.įifth, write the code in the body of the stored function in the BEGIN END block. Third, specify the data type of the return value in the RETURNS statement, which can be any valid MySQL data types.įourth, specify if a function is deterministic or not using the DETERMINISTIC keyword.Ī deterministic function always returns the same result for the same input parameters whereas a non-deterministic function returns different results for the same input parameters. ![]() You cannot specify IN, OUT or INOUT modifiers to parameters By default, all parameters are the IN parameters. Second, list all parameters of the stored function inside the parentheses followed by the function name. DETERMINISTIC BEGIN - statements END $$ĭELIMITER Code language: SQL (Structured Query Language) ( sql )įirst, specify the name of the stored function that you want to create after CREATE FUNCTION keywords. The following illustrates the basic syntax for creating a new stored function: DELIMITER $$ To create a stored function, you use the CREATE FUNCTION statement. This helps improve the readability and maintainability of the procedural code. Typically, you use stored functions to encapsulate common formulas or business rules that are reusable among SQL statements or stored programs.ĭifferent from a stored procedure, you can use a stored function in SQL statements wherever an expression is used. You just need to create them directly in the database and then display it in the tool.Summary: in this tutorial, you will learn how to create stored functions using the CREATE FUNCTION statement.Ī stored function is a special kind stored program that returns a single value. In Scriptcase it is possible to use customized procedures in forms, for example. If the parameter is not informed or the informed parameter is of the wrong type, an error message will appear. If the command is not modified, the database reports an error indicating that there is already a procedure created by that name.Īs for naming, using “sp_” before the name of the procedure helps to standardize the database.įinally, the procedure call in the database’s management screen will be as follows: After the procedure is created, you must use the ALTER command so that subsequent amendments are applied.
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