Re: Unpredictable results from stored procedure

[Peter Brawley]

> It's not possible in my project to replace LIKE and REGEXP with =

?!? None of the data values your code applies Like to contain wildcard chars; in such cases, Like is equivalent to =, ie use of RLike here is incoherent. Likewise none of the data values the code applies RegExp to have Regex chars, so again RegExp is equivalent to =, ie use of RegExp here is incoherent.

I can't reproduce your problem NULL results in MySQL 5.6, so I've no idea whether the problem arises from your incorrect use of RLike and RegExp, or from a 5.0 bug. If changing those operators to = does not fix the problem, consider upgrading to 5.6.