Updating columns within a Cursor For Loop - plsql

Question

I'm running a CURSOR FOR LOOP, and among the things I'm trying to do, is to update a column for each record, with the day on which the loop was run. I've included the following statement within the loop
UPDATE SALES_TABLE
SET SETTLEMENTDATE = SYSDATE
WHERE RECEIPTNO= R1.RECEIPTNO;
In this case, RECEIPTNO is a PK, if that makes any difference. Any idea what I'm doing wrong? The SETTLEMENTDATE column just remains NULL.
UPDATED WITH GREATER FOR LOOP VISIBILITY
FOR R1 IN c_dbfData LOOP
...
UPDATE SALES_TABLE
SET SETTLED = 'Y'
WHERE RECEIPTNO = R1.RECEIPTNO;
UPDATE SALES_TABLE
SET SETTLEMENTDATE = SYSDATE
WHERE RECEIPTNO= R1.RECEIPTNO;
END LOOP;
All I've excluded with the ellipsis is just writing to a file, which works fine.

Answer 1

I suggest you modify your code as follows:
DBMS_OUTPUT.PUT_LINE('Entering update loop');
DECLARE
nRows_read NUMBER := 0;
BEGIN
FOR R1 IN c_dbfData LOOP
nRows_read := nRows_read + 1;
DBMS_OUTPUT.PUT_LINE('In loop, R1.RECEIPTNO=' || R1.RECEIPTNO);
BEGIN
... -- put your file logic here
EXCEPTION
WHEN OTHERS THEN
DBMS_OUTPUT.PUT_LINE('Error in file logic: SQLCODE=' || SQLCODE ||
' SQLERRM=' || SQLERRM);
RAISE;
END;
BEGIN
UPDATE SALES_TABLE
SET SETTLED = 'Y'
WHERE RECEIPTNO = R1.RECEIPTNO;
DBMS_OUTPUT.PUT_LINE(' First update successful for RECEIPTNO=' ||
R1.RECEIPTNO ||
', ' || SQL%ROWCOUNT || ' rows updated');
EXCEPTION
WHEN OTHERS THEN
DBMS_OUTPUT.PUT_LINE('Error in first UPDATE for RECEIPTNO=' ||
R1.RECEIPTNO || ': SQLCODE=' || SQLCODE ||
' SQLERRM=' || SQLERRM);
RAISE;
END;
BEGIN
UPDATE SALES_TABLE
SET SETTLEMENTDATE = SYSDATE
WHERE RECEIPTNO= R1.RECEIPTNO;
DBMS_OUTPUT.PUT_LINE(' Second update successful for RECEIPTNO=' ||
R1.RECEIPTNO ||
', ' || SQL%ROWCOUNT || ' rows updated');
EXCEPTION
WHEN OTHERS THEN
DBMS_OUTPUT.PUT_LINE('Error in second UPDATE for RECEIPTNO=' ||
R1.RECEIPTNO || ': SQLCODE=' || SQLCODE ||
' SQLERRM=' || SQLERRM);
RAISE;
END;
END LOOP;
DBMS_OUTPUT.PUT_LINE('Update loop complete, ' || nRows_read || ' rows read');
EXCEPTION
WHEN OTHERS THEN
DBMS_OUTPUT.PUT_LINE('Error caught in outer handler after ' || nRows_read ||
'rows: SQLCODE=' || SQLCODE ||
' SQLERRM=' || SQLERRM');
RAISE;
END;
Then examine the DBMS_OUTPUT from the above. You should ideally see a list of the RECEIPTNO's which were processed, and a line for each update noting how many rows were altered by the update.
Alternatively, if you're using a tool such as PL/SQL Developer which provides easy access to the Oracle PL/SQL debugger you could leave out the internal PUT_LINE's and just set breakpoints on the PUT_LINE calls in the EXCEPTION blocks and then run your procedure under the debugger to see if it hits either of the breakpoints.
Share and enjoy.

Answer 2

I it's not a problem with the commit logic, something must be off with the where clause (RECEIPTNO=R1.RECEIPTNO). Either R1.RECEIPTNO does not contain the values you would expect or the table sales_table is not populated as you expect.
Generally speaking:
- it would be twice as fast, to combine the two update sin your example
- even faster if you can update in a single statement without the procedural loop