I presume you're talking about a string comparison in a mySQL "select". If so:
1. I thought that, in most cases, mysQL selects *were* case insensitive:
http://dev.mysql.com/doc/refman/5.0/...nsitivity.html
2. I also thought "collation order" was a property of the database when you create it, and not something you can turn on and off on a per-session or per-statement basis. This is true for Oracle and SQL-Server, the above link suggests that it's also true of mySQL (at least for that particular version of mySQL).
3. mySQL lets you use REGEXP (I don't know if mySQL regular expressions support the "i" qualifier, to make the comparison case insensitive).
... and, finally ...
4. You can always use LCASE() or UCASE() with your expression (making the string all-lower or all-upper case, respectively).
'Hope that helps .. PSM