Question

What I have is a table with the following columns

All columns are nvarchar expect for the Date columns which are datetime

CreateDateA InvIDA StorageIDA CreateDateB InvIDB StorageIDB UniID


What I want to do is move the values on each row (based on UniID) into the represenative B columns where UniID is 1 less, so the ‘A’ columns where UniID = 2 should go to the B Columns where the UniID = 1.

This is the query i’m using but it’s not updating any columns.

update InvSubmission
set CreateDateB = CreateDateA,
InvIDB = InvIDA ,
StorageIDB = StorageIDA 
where StorageIDB = StorageIDA and UniID = (select UniID-1 from InvSubmission)

There is multiple storageid’s in this table, however, each record has a match to at least one other row.

Answer 1

@PinnyM’s answer is close, but in SQL Server, you have to name the updated table in the from clause also:

update toUpdate
set CreateDateB = sourceTable.CreateDateA,
    InvIDB = sourceTable.InvIDA
FROM
    InvSubmission toUpdate
        inner Join
    InvSubmission sourceTable
       ON sourceTable.UniID = toUpdate.UniID + 1
       AND sourceTable.StorageIDA = toUpdate.StorageIDB

Otherwise, this note becomes relevant:

If the object being updated is the same as the object in the FROM clause and there is only one reference to the object in the FROM clause, an object alias may or may not be specified

And then you’re suffering the same problem that @Yuck pointed out – you’re trying to compare the UniID value within a single row to a value one less than itself.