Question

I am not a MYSQL developer, but just had to write some code. Please accept my apologies if I am doing anything silly in my code.

My need is to get a single row like select * from users where userID = 1 limit 1 and assign it to a variable and access columns for doing some calculation. Firstly, is this possible?
I have tried to go through step by step, that is why I wrote a simple function like below

    DELIMITER $$

CREATE DEFINER=`user`@`%` FUNCTION `GetReportees`(userid VARCHAR(255)) RETURNS varchar(50) CHARSET latin1
    DETERMINISTIC
BEGIN

    DECLARE Var1 varchar(120);
    DECLARE Var2 varchar(120);
    Select @Var1=forename, @Var2=surname from company_users.users where userID = @userid limit 1;
    return @Var1;
END

when I try to save this function, it says that ERROR 1415: Not allowed to return a result set from a function. But I clearly return a varchar variable.

Could anyone tell me what I am doing wrong? it should not be this much hard, I believe.

Many thanks

Regards

Answer 1

You should read the documentation on the difference between user-defined variables and local variables.

In your example, you have a parameter and 2 local variables, so you should use them like this:

    DELIMITER $$

CREATE DEFINER=`user`@`%` FUNCTION `GetReportees`(p_userid VARCHAR(255)) 
    RETURNS varchar(120) CHARSET latin1
    DETERMINISTIC
BEGIN

    DECLARE Var1 varchar(120);
    DECLARE Var2 varchar(120);

    Select forename, surname 
    into Var1,Var2
    from company_users.users 
    where userID = p_userid 
    limit 1;

    return Var1;
END