Question

I am trying to update a table so that all values become identical to another table on a different database. I can do it with an insert command but not an update command.

This works:

INSERT [test1].[dbo].[table1]
    SELECT * FROM [source].[dbo].[table1]

This does not:

UPDATE [test2].[dbo].[table1] 
SET [source].[dbo].[table1] = [test2].[dbo].[table1]

nor this:

UPDATE [test2].[dbo].[table1]
SET 
     [test2].[dbo].[table1].[PKcolumn] = [source].[dbo].[table1].[PKcolumn]
    ,[test2].[dbo].[table1].[column2] = [source].[dbo].[table1].[column2] 
    ,[test2].[dbo].[table1].[column3] = [source].[dbo].[table1].[column3] 

WHERE
    [source].[dbo].[table1].[PKcolumn] = [test2].[dbo].[table1].[PKcolumn]

The result is always some variation of this error message despite checking for errors countless times:

Msg 4104, Level 16, State 1, Line 1

The multi-part identifier “source.dbo.table1.PKColumn” could not be bound.

Any Suggestions?

Answer 1

Since update can only affect one table, you don’t have to specify it:

UPDATE dest
SET    column2 = src.column2
FROM   source.dbo.table1 as src
JOIN   test2.dbo.table1 as dest
on     dest.PKcolumn = src.PKcolumn

P.S. Depending on which database you’re using, you might want to check out the MERGE statement.