How to use case with condition inside a function in mysql?

by mallory_cormier , in category: MySQL , 2 months ago

How to use case with condition inside a function in mysql?

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1 answer

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by ryleigh , 2 months ago

@mallory_cormier 

To use a case statement with conditions inside a function in MySQL, you can follow these steps:

  1. Create a function using the CREATE FUNCTION statement. Specify the function name, input parameters (if any), and the return type.
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CREATE FUNCTION myFunctionName(param1 INT, param2 VARCHAR(255)) RETURNS INT
BEGIN
    -- function logic goes here
END;


  1. Use the CASE statement within the function to set up the conditions and the corresponding actions.
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CREATE FUNCTION myFunctionName(param1 INT, param2 VARCHAR(255)) RETURNS INT
BEGIN
    DECLARE result INT;
    
    SET result = CASE
        WHEN param1 > 10 THEN 1
        WHEN param1 = 5 AND param2 = 'abc' THEN 2
        ELSE 0
    END;
    
    RETURN result;
END;


In the above example, the function receives two parameters (param1 and param2). It uses the CASE statement with conditions to determine the value of the result variable. If param1 is greater than 10, result is set to 1. If param1 is equal to 5 and param2 is equal to 'abc', result is set to 2. Otherwise, result is set to 0.

  1. Customize the conditions and actions of the CASE statement to fit your specific requirements. You can have multiple conditions and actions inside a CASE statement.
  2. Use the RETURN statement at the end of the function to specify the value to be returned.
  3. Lastly, call the function using the SELECT statement.
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SELECT myFunctionName(15, 'xyz');


The above statement would call myFunctionName with the arguments 15 and 'xyz' and return the result of the function execution, which can be used in further calculations or displayed as required.