basic oracle update statement

Question

I am writing a stored procedure using oracle. I am new to oracle, and stored procedures, but what I am trying to do seems fairly straight forward, yet I am having trouble.

I have 2 tables BATCH_ISA and BATCH_TEMP

the temp table was created with records from the BATCH_ISA as well as a few other tables. I need to update a flag in the BATCH_ISA table from 'Y' to 'N' after the records have been successfully moved into the BATCH_TEMP table.

I am trying to do an update for all the the records in BATCH_ISA where the ISA_KEY field is found in both of the tables, and setting the flag to 'N'

What is the basic update statement I should use?

Answer 1

-- SET EVERYTHING TO 'N' FIRST:
UPDATE BATCH_ISA 
SET
    FLAG = 'N';

-- NOW UPDATE ONLY MATCHED ROWS TO 'Y':
UPDATE BATCH_ISA 
SET
    FLAG = 'Y' 
WHERE
    EXISTS (
        SELECT * FROM BATCH_TEMP
        WHERE BATCH_ISA.ISA_KEY = BATCH_TEMP.ISA_KEY
);

COMMIT;

I removed the commit after the first update, but if there are plenty of rows you could use it to save redolog overhead.