/// Implements <CompareExpr> ::= <Value> IS NUll
public Reduction CreateRULE_COMPAREEXPR_IS_NULL(Reduction reduction)
{
object lhs = ((Reduction)((Token)reduction.GetToken(0)).Data).Tag;
Predicate predicate = new IsNullPredicate(lhs as IFunctor);
reduction.Tag = predicate;
if (NCacheLog.IsInfoEnabled)
{
NCacheLog.Info("RULE_COMPAREEXPR_IS_NULL");
}
return(null);
}
void IVisitor.VisitBefore(IsNullPredicate predicate)
{
this.ParentExists(predicate);
}
void IVisitor.VisitAfter(IsNullPredicate predicate)
{
this.ParentExists(predicate);
}
public void VisitIsNullPredicate(SqlFragment parent, IsNullPredicate isNullPredicate)
{
isNullPredicate.Operand.Build(parent, this);
this.Script.Append("IS NULL");
}
public abstract void Visit(IsNullPredicate predicate);
