where() accepts an arbitrary number of parameters. Each parameter
must contain a logical expression or an array with logical expressions.
If you specify multiple logical expression they are connected using
a logical and.
where() could be invoked several times. All provided arguments
added to the end of $whereString and form final WHERE clause of the query.
Example:
$q->update( 'MyTable' )->where( $q->expr->eq( 'id', 1 ) );
