Delete rows from one table based on multiple tables

Question

I have three tables Table1, Table2 and Table3 and the following query which deletes rows in Table2

delete from Table2 
where EXISTS
(select (1) from Table1
 where Table1.col1=Table2.col1
 AND   Table1.col2=Table2.col2
 AND   Table1.col3=(select **Table3.col3 from Table3** inner join Table2 on Table3.col1=Table2.col1)

If col3 of Table1 matches with col3 of Table3 and col1,col2 of Table1 matches with col1,col2 of Table2 then I need to delete the row from Table2. However I am unable to use Table3 in this query. Please help

Answer 1

Something like this should do the trick:

delete from 
    Table2 t2
where 
    Exists (
        select
            'x'
        from 
            Table1 t1 
                inner join
            Table3 t3
                on t1.col3 = t3.col3
        where
            t1.col1 = t2.col1 and
            t1.col2 = t2.col2
 );

Answer 2

You might benefit from using the merge into statement. It's hard to distinguish every relationship in your Table1,2,3 and Col1,2,3 example names, but it might look like this:

merge into Table2 t2
using
  (select
    t2.id
  from
    Table1 t1
    inner join Table2 t2 on t2.col1 = t1.col1 and t2.col2 = t1.col2
    inner join Table3 t3 on t3.col3 = t1.col3 and t3.col1 = t2.col1
  ) t2x
on (t2.id = t2x.id)
when matched then
  delete;

Which is basically the same as

delete from Table2 t2 
where
  t2.id in
    (select
      t2.id
    from
      Table1 t1
      inner join Table2 t2 on t2.col1 = t1.col1 and t2.col2 = t1.col2
      inner join Table3 t3 on t3.col3 = t1.col3 and t3.col1 = t2.col1
    )