MySQL: How to use MAX function in WHERE clause? - mysql

Question

This is what my query generated.
LOANTYPE | TOTALBALANCE | STATUS |
--------------------|--------------|--------|
Conventional Loans | 52.84 | Active |
Conforming Loans | 45.55 | Active |
Non-Conforming Loans| 43.90 | Active |
Secured Loans | 42.73 | Active |
Unsecured Loans | 34.99 | Active |
Open-ended Loans | 11.99 | Active |
Close-ended Loans | 11.69 | Active |
The TOTALBALANCE column is the summation of both Active and Inactive accounts per LOANTYPE.
Here is my query
SELECT
product.LOANTYPE,
SUM(account.PRINCIPALBALANCE + account.INTERESTBALANCE) AS TOTALBALANCE,
IF(DATE_ADD(MAX(transaction.PAYMENTDATES),
INTERVAL 6 MONTH) > CURRENT_DATE(),
'Active',
'Innactive') AS LOANSTATUS
FROM
account
INNER JOIN
client ON account.ACCOUNTKEY = client.PRIMARYKEY
INNER JOIN
product ON account.PRODUCTKEY = product.PRIMARYKEY
INNER JOIN
transaction ON transaction.ACCOUNTKEY = loanaccount.PRIMARYKEY
WHERE
transaction.TYPE = 'REPAYMENT'
GROUP BY product.LOANTYPE
I would like to get the TOTALBALANCE of Active/Innactive accounts as well as how many are Active/Inactive per LOANTYPE like so.
LOANTYPE | ACTIVEBALANCE | ACTIVE# | INACTIVEBALANCE | INNACTIVE#
--------------------|---------------|---------|-----------------|------------
Conventional Loans | 35.23 | 2 | 17.61 | 1
Conforming Loans | 18.22 | 1 | 27.33 | 1
Non-Conforming Loans| 32.486 | 2 | 11.414 | 2
Secured Loans | 17.092 | 2 | 25.638 | 1
Unsecured Loans | 40.61 | 2 | 5.6112 | 1
Open-ended Loans | 7.194 | 1 | 4.796 | 1
Close-ended Loans | 6.4395 | 2 | 5.26 | 2
I added
AND DATE_ADD(MAX(transaction.PAYMENTDATES),INTERVAL 6 MONTH) > CURRENT_DATE() in WHERE Clause
to limit the results but it still give me error.
What would/should I modify in my query to make my idea happen.
Thank you for your time.

Answer 1

Use conditional aggregation. The basic idea below is that we use a CASE expression to conditionally take a sum of balance, or record count, depending on whether the records are classified as active or inactive.
SELECT
product.LOANTYPE,
SUM(CASE WHEN DATE_ADD(t.PAYMENTDATES, INTERVAL 6 MONTH) > CURRENT_DATE()
THEN account.PRINCIPALBALANCE + account.INTERESTBALANCE
ELSE 0 END) AS ACTIVEBALANCE,
COUNT(CASE WHEN DATE_ADD(t.PAYMENTDATES, INTERVAL 6 MONTH) > CURRENT_DATE()
THEN 1 END) AS ACTIVE_CNT,
SUM(CASE WHEN DATE_ADD(t.PAYMENTDATES, INTERVAL 6 MONTH) <= CURRENT_DATE()
THEN account.PRINCIPALBALANCE + account.INTERESTBALANCE
ELSE 0 END) AS INACTIVEBALANCE,
COUNT(CASE WHEN DATE_ADD(t.PAYMENTDATES, INTERVAL 6 MONTH) <= CURRENT_DATE()
THEN 1 END) AS INACTIVE_CNT
FROM account a
INNER JOIN client c
ON a.ACCOUNTKEY = c.PRIMARYKEY
INNER JOIN product p
ON a.PRODUCTKEY = p.PRIMARYKEY
INNER JOIN
(
SELECT ACCOUNTKEY, MAX(PAYMENTDATES) AS PAYMENTDATES
FROM transaction
WHERE TYPE = 'REPAYMENT'
GROUP BY ACCOUNTKEY
) t
ON t.ACCOUNTKEY = a.PRIMARYKEY
GROUP BY
p.LOANTYPE;
Note that in your question you refer to a loanaccount table, but this table appears nowhere in the actual query. I have assumed that you intended this to refer to the account table.

Answer 2

How about this
SELECT product.loantype,
active.totalbalance AS ACTIVEBALANCE,
active.cnt AS ACTIVE,
incative.totalbalance AS INACTIVEBALANCE,
inactive.cnt AS INACTIVE
FROM product
left join (SELECT product.loantype,
SUM(account.principalbalance
+ account.interestbalance) AS TOTALBALANCE,
COUNT(1) AS cnt
FROM account
inner join client
ON account.accountkey = client.primarykey
inner join product
ON account.productkey = product.primarykey
WHERE TRANSACTION.TYPE = 'REPAYMENT'
AND Current_date() > (SELECT DATE_ADD(MAX(
TRANSACTION.paymentdates),
interval 6 month)
FROM TRANSACTION
WHERE TYPE = 'REPAYMENT'
AND TRANSACTION.accountkey
=
account.accountkey)
GROUP BY product.loantype) AS active
ON( product.loantype = active.loantype )
left join (SELECT product.loantype,
SUM(account.principalbalance
+ account.interestbalance) AS TOTALBALANCE,
COUNT(1) AS cnt
FROM account
inner join client
ON account.accountkey = client.primarykey
inner join product
ON account.productkey = product.primarykey
WHERE TRANSACTION.TYPE = 'REPAYMENT'
AND Current_date() < (SELECT DATE_ADD(MAX(
TRANSACTION.paymentdates),
interval 6 month)
FROM TRANSACTION
WHERE TYPE = 'REPAYMENT'
AND TRANSACTION.accountkey
=
account.accountkey)
GROUP BY product.loantype) AS inactive
ON( product.loantype = inactive.loantype )