How do I LIMIT the number of rows in a DELETE with DB2?

Question

I want to add a security on a sensitive table when I delete lines with an SQL request on a DB2 table.

I want to mimic the way MySQL allows you to limit the numbers o

Answer 1

Just select a statement, and put the statement inside the delete query:

delete from (
select from table WHERE info = '1' order by id fetch first 25000 rows only
)

Answer 2

delete from table where id in (select id from table where info = '1' order by id fetch first 1 rows only)

Answer 3

MERGE INTO XYZ A<BR>
USING (<BR>
SELECT RID_BIT(B) CHAVE<BR>
FROM XYZ B<BR>
FETCH FIRST 100000 ROWS ONLY) B<BR>
ON RID_BIT(A) = B.CHAVE<BR>
WHEN MATCHED THEN DELETE;

Answer 4

If your primary key has multiple values, or you just need multiple values as the condition, this is the query that works:

DELETE FROM TABLE
WHERE (COLUMN1, COLUMN2) IN (
    SELECT COLUMN1, COLUMN2 FROM TABLE
    WHERE SOME_COLUMN='THIS'
    AND SOME_OTHER_COLUMN LIKE 'THAT%'
    FETCH FIRST 10 ROWS ONLY)

Answer 5

How is this query?

delete from table D where exists 
 ( select * from ( select * from table M fetch first 10 rows only ) as M
   where M.object_id = D.object_id )

Answer 6

DELETE                                      
FROM Bibl/File                             
WHERE RRN(File) =  (                        
                    SELECT min(RRN(File))   
                    FROM Bibl/File         
                    WHERE Fld1 = 'xx'     
                   )   

The RRN function is to AS400/iSeries/PowerSystem alone. In other environments there are other functions for the relative record number.

This makes it possible to erase a record of several identical even without UNIQUE key. It can also be used to update with minor changes.

works like the LIMIT but with DELETE and / or UPDATE.

It only works on SQL DB2 in other settings should be changed by RRN function to return the column number