Subquery with DB2

[wrangler2004]

Hello all,

I am supporting an application running on DB2 8.2 on a Windows 2003 Server. The DB contains 2 tables in which I need to do a subquery. Table 1 contains and autogenerated primary key. For each row inserted into table 2, a reference to the PK in table 1 gets inserted into the FK_TABLE1 column. This is all done internal to our application and is not using db2's built-in support for primary/foreign keys (doh!).

Basically, I would like to write a query that ensures that for every row in TABLE2, there is a PK in TABLE1. To do this do I need to use a Join, or IN statement or what?? Any advice would be appreciated.

Here's an example of the data:

TABLE1:
PK
COL2
COL3
ETC....


TABLE2:
FK_TABLE1
COL2
COL3
ETC...

[kalexin]

Hello all,

I am supporting an application running on DB2 8.2 on a Windows 2003 Server. The DB contains 2 tables in which I need to do a subquery. Table 1 contains and autogenerated primary key. For each row inserted into table 2, a reference to the PK in table 1 gets inserted into the FK_TABLE1 column. This is all done internal to our application and is not using db2's built-in support for primary/foreign keys (doh!).

Basically, I would like to write a query that ensures that for every row in TABLE2, there is a PK in TABLE1. To do this do I need to use a Join, or IN statement or what?? Any advice would be appreciated.

Here's an example of the data:

TABLE1:
PK
COL2
COL3
ETC....


TABLE2:
FK_TABLE1
COL2
COL3
ETC...

Use a select statement, count distinct on both the key colums of the two tables. Is this what you are looking for?
BTW I think you can implement a simple trigger to take care of the data integrity between those two tables.