I can certainly do this by iterating through results with PHP, but just wanted to know if someone had a second to post a better solution.
The scenario is that I have a list of transactions. I select two dates and run a report to get the transactions between those two dates...easy. For one of the reporting sections though, I need to only return the transaction if it was their first transaction.
Here was where I got with the query:
SELECT *, MIN(bb_transactions.trans_tran_date) AS temp_first_time
FROM
bb_business
RIGHT JOIN bb_transactions ON bb_transactions.trans_store_id = bb_business.store_id
LEFT JOIN bb_member ON bb_member.member_id = bb_transactions.trans_member_id
WHERE
bb_transactions.trans_tran_date BETWEEN '2010-08-01' AND '2010-09-13'
AND bb_business.id = '5651'
GROUP BY bb_member.member_id
ORDER BY bb_member.member_id DESC
This gives me the MIN
of the transactions 开发者_StackOverflow中文版between the selected dates. What I really need is the overall MIN
if it falls between the two dates. Does that make sense?
I basically need to know if a customers purchased for the first time in the reporting period.
Anyways, no huge rush as I can solve with PHP. Mostly for my own curiosity and learning.
Thanks for spreading the knowledge!
EDIT:
I had to edit the query because I had left one of my trial-errors in there. I had also tried to use the temporary column created from MIN
as the selector between the two dates. That returned an error.
SOLUTION: Here is the revised query after help from you guys:
SELECT * FROM (
SELECT
bb_member.member_id,
MIN(bb_transactions.trans_tran_date) AS first_time
FROM
bb_business
RIGHT JOIN bb_transactions ON bb_transactions.trans_store_id = bb_business.store_id
LEFT JOIN bb_member ON bb_member.member_id = bb_transactions.trans_member_id
WHERE bb_business.id = '5651'
GROUP BY bb_member.member_id
) AS T
WHERE T.first_time BETWEEN '2010-08-01' AND '2010-09-13'
If we do a minimum of all transactions by customer, then check to see if that is in the correct period we get something along the lines of...
This will simply give you a yes/no flag as to whether the customer's first purchase was within the period...
SELECT CASE COUNT(*) WHEN 0 THEN 'Yes' ELSE 'No' END As [WasFirstTransInThisPeriod?]
FROM (
SELECT bb_member.member_id As [member_id], MIN(bb_transactions.trans_tran_date) AS temp_first_time
FROM bb_business
RIGHT JOIN bb_transactions ON bb_transactions.trans_store_id = bb_business.store_id
LEFT JOIN bb_member ON bb_member.member_id = bb_transactions.trans_member_id
WHERE bb_business.id = '5651'
GROUP BY bb_member.member_id
) T
WHERE T.temp_first_time BETWEEN '2010-08-01' AND '2010-09-13'
ORDER BY T.member_id DESC
(this is in T-SQL, but should hopefully give an idea of how this can be achieved similarly in mySQL)
Simon
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