I have an SQL Database and in it a table called InventoryAllocations. In the table I have multiple entries for DocumentID's and want to retrieve the last entry for each unique DocumentID. I can retrieve just one by doing
SELECT top(1) [UID]
,[RecordStatusID]
,[CreatedDate]
,[CreatedTime]
,[CreatedByID]
,[OperationType]
,[InventoryLocationID]
,[DocumentTypeID]
,[DocumentID]
,[SOJPersonnelID]
,[InventorySerialisedItemID]
,[TransactionQty]
,[TransactionInventoryStatusID]
,[Completed]
,[CreatedByType]
,[RecordTimeStamp]
FROM [CPData].[dbo].[InventoryAllocations]
order by DocumentID desc
but I want it to bring back a list containing all the unique DocumentID's.
SELECT TOP 1 WITH TIES
[UID]
,[RecordStatusID]
,[CreatedDate]
,[CreatedTime]
,[CreatedByID]
,[OperationType]
,[InventoryLocationID]
,[DocumentTypeID]
,[DocumentID]
,[SOJPersonnelID]
,[InventorySerialisedItemID]
,[TransactionQty]
,[TransactionInventoryStatusID]
,[Completed]
,[CreatedByType]
,[RecordTimeStamp]
FROM
[CPData].[dbo].[InventoryAllocations]
ORDER BY
ROW_NUMBER() OVER(PARTITION BY DocumentID ORDER BY [RecordTimeStamp] DESC);
TOP 1
works with WITH TIES
here.
WITH TIES
means that when ORDER BY = 1
, then SELECT
takes this record (because of TOP 1
) and all others that have ORDER BY = 1
(because of WITH TIES
).