get max date when sum of a field equals a value - sql

Question

I have a problem with writing a query.
Row data is as follow :
DATE CUSTOMER_ID AMOUNT
20170101 1 150
20170201 1 50
20170203 1 200
20170204 1 250
20170101 2 300
20170201 2 70
I want to know when(which date) the sum of amount for each customer_id becomes more than 350,
How can I write this query to have such a result ?
CUSTOMER_ID MAX_DATE
1 20170203
2 20170201
Thanks,

Answer 1

Simply use ANSI/ISO standard window functions to calculate the running sum:
select t.*
from (select t.*,
sum(t.amount) over (partition by t.customer_id order by t.date) as running_amount
from t
) t
where running_amount - amount < 350 and
running_amount >= 350;
If for some reason, your database doesn't support this functionality, you can use a correlated subquery:
select t.*
from (select t.*,
(select sum(t2.amount)
from t t2
where t2.customer_id = t.customer_id and
t2.date <= t.date
) as running_amount
from t
) t
where running_amount - amount < 350 and
running_amount >= 350;

Answer 2

ANSI SQL
Used for the test: TSQL and MS SQL Server 2012
select
"CUSTOMER_ID",
min("DATE")
FROM
(
select
"CUSTOMER_ID",
"DATE",
(
SELECT
sum(T02."AMOUNT") AMOUNT
FROM "TABLE01" T02
WHERE
T01."CUSTOMER_ID" = T02."CUSTOMER_ID"
AND T02."DATE" <= T01."DATE"
) "AMOUNT"
from "TABLE01" T01
) T03
where
T03."AMOUNT" > 350
group by
"CUSTOMER_ID"
GO
CUSTOMER_ID | (No column name)
----------: | :------------------
1 | 03/02/2017 00:00:00
2 | 01/02/2017 00:00:00
db<>fiddle here

Answer 3

DB-Fiddle
SELECT
tmp.`CUSTOMER_ID`,
MIN(tmp.`DATE`) as MAX_DATE
FROM
(
SELECT
`DATE`,
`CUSTOMER_ID`,
`AMOUNT`,
(
SELECT SUM(`AMOUNT`) FROM tbl t2 WHERE t2.`DATE` <= t1.`DATE` AND `CUSTOMER_ID` = t1.`CUSTOMER_ID`
) AS SUM_UP
FROM
`tbl` t1
ORDER BY
`DATE` ASC
) tmp
WHERE
tmp.`SUM_UP` > 350
GROUP BY
tmp.`CUSTOMER_ID`
Explaination:
First I select all rows and subselect all rows with SUM and ID where the current row DATE is smaller or same as all rows for the customer. From this tabe i select the MIN date, which has a current sum of >350

Answer 4

I think it is not an easy calculation and you have to calculate something. I know It could be seen a little mixed but i want to calculate step by step. As fist step if we can get success for your scenario, I believe it can be made better about performance. If anybody can make better my query please edit my post;
Unfortunately the solution that i cannot try on computer is below, I guess it will give you expected result;
-- Get the start date of customers
SELECT MIN(DATE) AS DATE
,CUSTOMER_ID
INTO #table
FROM TABLE t1
-- Calculate all possible date and where is sum of amount greater than 350
SELECT t1.CUSTOMER_ID
,SUM(SELECT Amount FROM TABLE t3 WHERE t3.DATE BETWEEN t1.DATE
AND t2.DATE) AS total
,t2.DATE AS DATE
INTO #tableCalculated
FROM #table t1
INNER JOIN TABLE t2 ON t.ID = t2.ID
AND t1.DATE != t2.DATE
WHERE total > 350
-- SELECT Min amount and date for per Customer_ID
SELECT CUSTOMER_ID, MIN(DATE) AS DATE
FROM #tableCalculated
GROUP BY ID

Answer 5

SELECT CUSTOMER_ID, MIN(DATE) AS GOALDATE
FROM ( SELECT cd1.*, (SELECT SUM(AMOUNT)
FROM CustData cd2
WHERE cd2.CUSTOMER_ID = cd1.CUSTOMER_ID
AND cd2.DATE <= cd1.DATE) AS RUNNINGTOTAL
FROM CustData cd1) AS custdata2
WHERE RUNNINGTOTAL >= 350
GROUP BY CUSTOMER_ID
DB Fiddle