C-style escapes in SQLite

[ckristo]

Hi,

I recently experienced a problem with a custom CGridView filter that allows to filter email addresses using partial matching. The filter wasn't working when an underscore character ('_') was present in the filter condition. After investigating a bit, I found out that SQLite doesn't support C-style escaping (cf. https://www.sqlite.org/lang_expr.html) which is used by Yii's DBAL by default (e.g. by CDbCriteria.addSearchCondition or by CDbCommandBuilder.createSearchCondition). In SQLite, you need to extend the LIKE expression by an ESCAPE clause (cf. http://stackoverflow.com/a/7323498).

There's a custom CDbCommandBuilder implementation for SQLite which could be easily adapted / extended, but not for CDbCriteria. Any idea how we could solve this there?