mysql use IF NOT NULL as part of transaction

Question

I am using a MySQL transaction. If the initial where myHistoryNum result (match name+rowActive) is not NULL, then continue the transaction.

I have tried various combinations, however cannot get the insert statement to trigger when myHistoryNum is set.

history | uuid | name  | rowActive
24      | abcd | Art   | 1          <<< is match, trigger an insert
999     | zxcv | Art   | 0          <<< no match, do not trigger insert

start transaction; 
select @myHistNum := max(history), @olduuid := uuid 
from mytable WHERE (name=art AND rowActive=1);

# START IS NOT NULL test
CASE WHEN @myHistNum IS NOT NULL THEN
set @histNum = @histNum  + 1;
INSERT INTO mytable 
.....
END;                                      <<<ALT, tried END AS;
commit;

also tried

IF @myHistNum IS NOT NULL
 THEN 
   .....
END IF;
commit;

Possible duplicate of [MySQL Conditional Insert](https://stackoverflow.com/questions/913841/mysql-conditional-insert) — Nick, Dec 03 '18 at 22:26

score 0 · Answer 1 · answered Dec 03 '18 at 21:19

0

If I'm not mistaken, control flow statements (like IF, WHEN) can only be used within stored programs in MySQL

answered Dec 03 '18 at 21:19

fifonik

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mysql use IF NOT NULL as part of transaction

1 Answers1