case Between = ' between';
case BetweenNot = ' not between';
case Bigger = '>';
case BiggerEqual = '>=';
case Different = '<>';
case Equal = '=';
case Exists = 'exists';
case ExistsNot = 'not exists';
case In = ' in';
case InNot = ' not in';
case IsNotNull = ' not null';
case Like = ' like ';
case Smaller = '<';
case SmallerEqual = '<=';