How to properly loop in a stored function on MySQL?

Question

I am having some difficulty getting a pretty simple stored procedure right. Consider the following article table snippet:

id    replaced_by     baseID
 1             


        

Answer 1

From mysql :

If the query returns no rows, a warning with error code 1329 occurs (No data), and the variable values remain unchanged

So you have an infinite loop when no records found with a given x (y remains unchanged) Try SET y = (SELECT id ....) instead or add SET y = null before your select statement (it should be the first statement in the loop)