I have the database of ATM card in which there are fields account_no,card_no,is_blocked,is_activated,issue_date Fields account number and card numbers are not unique as old card will be expired and marked as is_block=Y and another record with same card number ,account number will be inserted into new row with is_blocked=N . Now i need to update is_blocked/is_activated with help of issue_date i.e
UPDATE card_info set is_blocked='Y' where card_no='6396163270002509'
AND opening_date=(SELECT MAX(opening_date) FROM card_info WHERE card_no='6396163270002509')
but is doesn't allow me to do so it throws following error
1093 - You can't specify target table 'card_info' for update in FROM clause
Try this instead:
UPDATE card_info ci
INNER JOIN
(
SELECT card_no, MAX(opening_date) MaxOpeningDate
FROM card_info
GROUP BY card_no
) cm ON ci.card_no = cm.card_no AND ci.opening_date = cm.MaxOpeningDate
SET ci.is_blocked='Y'
WHERE ci.card_no = '6396163270002509'
That's one of those stupid limitations of the MySQL parser. The usual way to solve this is to use a JOIN query as Mahmoud has shown.
The (at least to me) surprising part is that it really seems a parser problem, not a problem of the engine itself because if you wrap the sub-select into a derived table, this does work:
UPDATE card_info
SET is_blocked='Y'
WHERE card_no = '6396163270002509'
AND opening_date = ( select max_date
from (
SELECT MAX(opening_date) as_max_date
FROM card_info
WHERE card_no='6396163270002509') t
)
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With