DISTINCT ONsyntax is described. But when I want to use this syntax in
CDbCriteria->distinct- only boolean value available. And CDbCommandBuilder at line #123 of the yiiframework v1.1.13 for example, created statement SELECT DISTINCT, and no opportunity to hook this. Will be good to set CDbCriteria->distinct property as string or as array otherwise boolean as now.
SELECT DISTINCT ON (expression [, expression ...]) select_list ...