Compare to fields and show which ones dont exists?

Question

Hi
I have two tables, one is SR_TRANSACTIONS and the other is SR_CUSTOMERS.
I want to report on which companies are listed in SR_TRANSACTIONS but not in SR_CUSTOMERS i.e which ones need to be added before this database goes live.
This is the query that shows a list of matching companies in both tables, could you suggest a modification of this code that shows which companies arent listed in SR_CUSTOMERS but are listed in SR_TRANSACTIONS?
select DISTINCT      "SR_CUSTOMERS"."NAME" as "NAME",
      "SR_TRANSACTIONS"."CUSTNAME" as "CUSTNAME"
from      "SR_TRANSACTIONS" "SR_TRANSACTIONS",
      "SR_CUSTOMERS" "SR_CUSTOMERS"
where   "SR_TRANSACTIONS"."CUSTNAME" = "SR_CUSTOMERS"."NAME" Thanks
Adam

Answer 1

Use an outer join, like in following example :
TEST@db102 > select * from dept;
    DEPTNO DNAME          LOC
        10 ACCOUNTING     NEW YORK
        20 RESEARCH       DALLAS
        30 SALES          CHICAGO
        40 OPERATIONS     BOSTON
TEST@db102 > create table dept1 as select * from dept;
Table created.
TEST@db102 > delete dept1 where deptno=30;
1 row deleted.
TEST@db102 > select a.* from dept a, dept1 b
  2  where a.deptno = b.deptno(+)
  3  and b.deptno is null;
    DEPTNO DNAME          LOC
        30 SALES          CHICAGO
TEST@db102 >