Need SQL Query to find Parent records without child records

Question

I am not at all conversant in SQL so was hoping someone could help me with a query that will find all the records in a parent table for which there are no records in a child

Answer 1

I simply dont understand whats the having clause doing in your query as I see already you are saying where ChildTable.ChildField_ = '2131' that already means you have record set for childfield 2131 Try the below query it would mean that if the parent doesnt have child in the Childtable with field 2131then o/p the same.

     SELECT    ParentTable.ParentID
         FROM      ParentTable 
         Where ParentTable.ParentID NOT IN (Select ChildID 
        From ChildTable where
         ChildTable.ChildField_ = '2131')