MySQL select one record into variable inside of the function using if then else approach

Question

I am trying to build a mysql function which, given input variables, is capable to go into one of the if branches and set a variable using a select. Then this variable should be returned. After browsing a bunch of manuals I settled on the code below:

create function dayssincelastmo(sedol varchar(255), currDate datetime, z_score double, groupnum int)
returns int
deterministic 
begin
    if zscore<0 then
        select datediff(p.`Period (Formatted)`, currDate) into @days
            from
                price as p
            where
                p.G_SEDOL = sedol
                and p.`Period (Formatted)`<=currDate
                and p.zscore<=z_score
                and p.`GRP MODEL NUM` = groupnum
                order by p.`Period (Formatted)`
                limit 1;
    end if;
    if zscore>=0 then
        select datediff(p.`Period (Formatted)`, currDate)  into @days
            from
                price as p
            where
                p.G_SEDOL = sedol
                and p.`Period (Formatted)`<=currDate
                and p.zscore>=z_score
                and p.`GRP MODEL NUM` = groupnum
                order by p.`Period (Formatted)`
                limit 1;
    end if;
return @days
end

As you see I limit number of outputs to 1 to get only one value from select in each of the branches. I also use if then else approach and close each of my if statements with end if.

But I get a error from the interpreter at line 15, which precisely has the limit 1; entry:

order by p.`Period (Formatted)`
**limit 1;**

Any advice on what is wrong?

Answer 1

Don't forget the semicolon (;) in RETURN statement:

...
-- return @days
return @days;
...

UPDATE

I can't reproduce the problem:

mysql> DROP FUNCTION IF EXISTS `dayssincelastmo`;
Query OK, 0 rows affected, 1 warning (0.00 sec)

mysql> DELIMITER //

mysql> create function dayssincelastmo(
    ->   sedol varchar(255),
    ->   currDate datetime,
    ->   z_score double,
    ->   groupnum int
    -> )
    -> returns int
    -> deterministic 
    -> begin
    ->     if zscore<0 then
    ->         select datediff(p.`Period (Formatted)`, currDate) into @days
    ->             from
    ->                 price as p
    ->             where
    ->                 p.G_SEDOL = sedol
    ->                 and p.`Period (Formatted)`<=currDate
    ->                 and p.zscore<=z_score
    ->                 and p.`GRP MODEL NUM` = groupnum
    ->                 order by p.`Period (Formatted)`
    ->                 limit 1;
    ->     end if;
    ->     if zscore>=0 then
    ->         select datediff(p.`Period (Formatted)`, currDate)  into @days
    ->             from
    ->                 price as p
    ->             where
    ->                 p.G_SEDOL = sedol
    ->                 and p.`Period (Formatted)`<=currDate
    ->                 and p.zscore>=z_score
    ->                 and p.`GRP MODEL NUM` = groupnum
    ->                 order by p.`Period (Formatted)`
    ->                 limit 1;
    ->     end if;
    -> return @days;
    -> end//
Query OK, 0 rows affected (0.01 sec)

mysql> DELIMITER ;