Select invoices based on quantity needed - sql

Question

I have a table that looks like this:
+---------------+---------------+------------------+--------------+
| InvoiceNumber | ProductNumber | ReceivedQuantity | ReceivedDate |
+---------------+---------------+------------------+--------------+
| INV001 | P001 | 500 | 09/01/2015 |
| INV002 | P001 | 600 | 09/02/2015 |
| INV003 | P001 | 700 | 09/03/2015 |
+---------------+---------------+------------------+--------------+
When a product is ordered. System needs to know which invoice it gets it from. First in first out.
For example I need 1000 quantity of product number P001. It should select the following invoices. It does not display the last invoice since 500 + 600 is already sufficient quantity
+---------------+---------------+------------------+--------------+
| InvoiceNumber | ProductNumber | ReceivedQuantity | ReceivedDate |
+---------------+---------------+------------------+--------------+
| INV001 | P001 | 500 | 09/01/2015 |
| INV002 | P001 | 600 | 09/02/2015 |
+---------------+---------------+------------------+--------------+
I can replicate this by making a cursor and looping through the table but looking for the best way to achieve this. Any nudge to the right direction would help a lot.

Answer 1

I think you can use a query like this:
;WITH t As (
SELECT *
, ROW_NUMBER() OVER (ORDER BY ReceivedDate, InvoiceNumber) As RowNo
FROM yourTable
), firstOverflow AS (
SELECT TOP(1)
t1.RowNo
FROM t t1
LEFT JOIN
t t2 ON t1.ProductNumber = t2.ProductNumber AND t1.ReceivedDate >= t2.ReceivedDate
GROUP BY t1.RowNo, t1.InvoiceNumber, t1.ProductNumber, t1.ReceivedQuantity, t1.ReceivedDate
HAVING SUM(t2.ReceivedQuantity) >= 1000
ORDER BY SUM(t2.ReceivedQuantity) - 1000)
SELECT *
FROM t
JOIN
firstOverflow ON t.RowNo <= firstOverflow.RowNo;
A better solution is this:
DECLARE #value int = 1000;
WITH t As (
SELECT *
, ROW_NUMBER() OVER (ORDER BY ReceivedDate, InvoiceNumber) As seq
FROM yourTable
), s As (
SELECT t.InvoiceNumber, t.ProductNumber, t.ReceivedQuantity, t.ReceivedDate, SUM(tt.ReceivedQuantity) As currentTotal
FROM t
LEFT JOIN
t tt ON t.ProductNumber = tt.ProductNumber AND t.seq >= tt.seq
GROUP BY t.InvoiceNumber, t.ProductNumber, t.ReceivedQuantity, t.ReceivedDate
), st As (
SELECT *
, ROW_NUMBER() OVER (ORDER BY (CASE WHEN s.currentTotal > #value THEN -currentTotal ELSE Null END) DESC) As seq
FROM s)
SELECT st.InvoiceNumber, st.ProductNumber, st.ReceivedQuantity, st.ReceivedDate
FROM st
WHERE currentTotal < #value
UNION ALL
SELECT st.InvoiceNumber, st.ProductNumber, st.ReceivedQuantity, st.ReceivedDate
FROM st
WHERE currentTotal >= #value AND st.seq = 1;

Answer 2

Try this query and give some feedback:
DECLARE #table TABLE (InvoiceNumber nvarchar(100),
ProductNumber nvarchar(100),
ReceivedQuantity int)
INSERT INTO #table VALUES ('inv001', 'p001', 500)
INSERT INTO #table VALUES ('inv002', 'p001', 600)
INSERT INTO #table VALUES ('inv003', 'p001', 600)
INSERT INTO #table VALUES ('inv004', 'p001', 600)
SQL 2012:
SELECT v.* FROM
(
SELECT t.*,
SUM(ReceivedQuantity) OVER (PARTITION BY ProductNumber ORDER BY InvoiceNumber) AS sum
FROM #table t
) v
WHERE sum <= 1000
SQL 2008:
SELECT v.* FROM
(
SELECT
a.InvoiceNumber
, a.ProductNumber
, SUM(b.ReceivedQuantity) AS sum
FROM
#table a
INNER JOIN #table b
ON a.InvoiceNumber >= b.InvoiceNumber AND a.ProductNumber = b.ProductNumber
GROUP BY
a.InvoiceNumber
, a.ProductNumber
) v
WHERE sum <= 1000