Question

Database has a table A, and a table B. A.ID is linked with B.ID.

I need to update all instances of A.Name to be equal to B.Catalog, if and only if those instances are linked A.ID = B.ID.

Only entries in A where A.Owner = 0 should be updated.

The code I have come up with is:

UPDATE A
SET A.Name = (SELECT B.Catalog
    FROM B, A
    WHERE (B.ID = A.ID) AND (A.Owner = 0))
WHERE A.ID IN (SELECT B.ID
    FROM B, A
    WHERE (B.ID = A.ID) AND (A.Owner = 0))

The error is "Subquery returned more than one value" (MS SQL 2005 adds "MSG 512, LEVEL 16, STATE 1, LINE 1"). I understand what the error is telling me, that I am trying to set a single value to be equal to the multiple results returned by the SELECT statement, but I think my knowledge of SQL is too lacking to come up with the proper code.

Any help would be greatly appreciated. This is what I get for trying to teach myself! A headache!

Answer 1

update A
set A.Name = B.Catalog
from TableA A
    join TableB B on
        A.Id = B.Id
where A.Owner = 0