Mysql LEFT JOIN with most recent record? - mysql

Question

I have this query:
SELECT A.ISIN, A.CUSIP, A.Currency, A.StatedFinalMaturityDate,
A.FirstPayDate, A.PaymentDelay, A.trancheName, A.DealTicker,
B.TrancheCoupon, B.OneMonthCoupon, B.SettleDate, B.Factor,
B.paymentDate
from table1 A
left JOIN table2 B on (A.DealTicker = B.DealTicker AND A.trancheName=B.trancheName)
where A.ISIN IN ('XS2004372095','XS1679333432','XS0333340361',
'XS0333337813','XS0333324241','XS0333323862',
'XS0333323516','XS0333323193','XS0333316908',
'XS0333313988','USWFMW0N9Z05','USWFHZ5XIY05',
'USWFHVA6TK04','USWFHTXSQJ03');
Here table1 have one record correspond to each ISIN but the table2 can have multiple rows.
table2 has settleDate column which show latest row. So I want to select only latest row from table2 only. Since table2 need two JOINING column I m little confused here.
PS: I cannot use mysql 8 features like row_number() as mysql server version is 5.7. And my table contains more than 150millions records. I tried a approaches but didn't work because of huge data.

Answer 1

You are using a very old MySQL version, so you cannot use windows functions but must access the same table twice. You can use NOT EXISTS or MAX to get the last rows. Here is an example with MAX:
SELECT
a.isin, a.cusip, a.currency, a.statedfinalmaturitydate, a.firstpaydate,
a.paymentdelay, a.tranchename, a.dealticker, b.tranchecoupon,
b.onemonthcoupon, b.settledate, b.factor, b.paymentdate
FROM table1 a
LEFT JOIN
(
SELECT *
FROM table2
WHERE (dealticker, tranchename, settledate) IN
(
SELECT dealticker, tranchename, max(settledate)
FROM table2
GROUP BY dealticker, tranchename
)
) b ON b.dealticker = a.dealticker AND b.tranchename = a.tranchename
where a.isin IN ('XS2004372095','XS1679333432','XS0333340361','XS0333337813',
'XS0333324241','XS0333323862','XS0333323516','XS0333323193',
'XS0333316908','XS0333313988','USWFMW0N9Z05','USWFHZ5XIY05',
'USWFHVA6TK04','USWFHTXSQJ03');

Answer 2

You can use window functions:
SELECT A.ISIN, A.CUSIP, A.Currency, A.StatedFinalMaturityDate, A.FirstPayDate, A.PaymentDelay, A.trancheName, A.DealTicker,
B.TrancheCoupon, B.OneMonthCoupon, B.SettleDate, B.Factor, B.paymentDate
FROM table1 A LEFT JOIN
(SELECT b.*,
ROW_NUMBER() OVER (PARTITION BY DealTicker, trancheName ORDER BY settleDate DESC) as seqnum
FROM table2 B
) B
ON A.DealTicker = B.DealTicker AND
A.trancheName = B.trancheName AND
B.seqnum = 1
WHERE A.ISIN IN ('XS2004372095','XS1679333432','XS0333340361','XS0333337813','XS0333324241','XS0333323862','XS0333323516','XS0333323193','XS0333316908','XS0333313988','USWFMW0N9Z05','USWFHZ5XIY05','USWFHVA6TK04','USWFHTXSQJ03');
In older versions of MySQL, you can use:
SELECT A.ISIN, A.CUSIP, A.Currency, A.StatedFinalMaturityDate, A.FirstPayDate, A.PaymentDelay, A.trancheName, A.DealTicker,
B.TrancheCoupon, B.OneMonthCoupon, B.SettleDate, B.Factor, B.paymentDate
FROM table1 A LEFT JOIN
table2 B
ON A.DealTicker = B.DealTicker AND
A.trancheName = B.trancheName AND
B.settleDate = (SELECT MAX(b2.settleDate)
FROM table2 b2
WHERE b2.DealTicker = B.DealTicker AND
b2.trancheName = B.trancheName
)
WHERE A.ISIN IN ('XS2004372095','XS1679333432','XS0333340361','XS0333337813','XS0333324241','XS0333323862','XS0333323516','XS0333323193','XS0333316908','XS0333313988','USWFMW0N9Z05','USWFHZ5XIY05','USWFHVA6TK04','USWFHTXSQJ03');