Question

I have a table defined like this

CREATE TABLE OrderItemRoomings(
    OrderItemRoomingId int IDENTITY(1,1) NOT NULL,
    OrderItemId int NOT NULL,
    PaxId int NOT NULL,
    GroupNumber tinyint NOT NULL)

I’m trying to get all OrderItemId which, when grouped, have differents group numbers

Assuming this table

+-----------------------------------+
| OrderItemId | PaxId | GroupNumber |
+-----------------------------------+
| 101         | 501   | 1           |
+-----------------------------------+
| 101         | 502   | 1           |
+-----------------------------------+
| 102         | 503   | 2           |
+-----------------------------------+
| 102         | 504   | 2           |
+-----------------------------------+
| 103         | 505   | 1           |
+-----------------------------------+
| 103         | 506   | 2           |
+-----------------------------------+

I want the query to returns 103 because there are two different group number for id 103.

I can’t figure out the GROUP BY query which would check all sub result detail.

Answer 1

SELECT OrderItemId
FROM MyTable
GROUP BY OrderItemID
HAVING COUNT(DISTINCT GroupNumber) > 1

Use HAVING to do filtering on grouped sets. Here we show only orderitemid records with more than one unique groupnumber value.