RE: SQL Gurus Wanted

["Joe Pluta" <joepluta@xxxxxxxxxxxxxxxxx>]

> From: Jon Paris
>
>  >> Yeah, it's called RPG <grin>.
>
> I'm still not seeing how your or Birgitta's solution identifies _which_
> columns in A are empty (i.e. they are blanks or nulls) and only update
> them from B when they are currently empty.  But I'll try to get my head
> around it this morning.

It doesn't!  That's not what you asked for.  You asked to update ALL data
columns in A if a record is in B.

To update a field only if its NULL, you have a way:

SET A.FIELD = COALESCE(A.FIELD, B.FIELD)

This will check A.FIELD for NULL and use B.FIELD instead.  Pretty
straightforward.  It's less easy with arbitrary values such as blanks.
You'll need something like this:

SET A.FIELD = (CASE A.FIELD WHEN ' ' THEN B.FIELD ELSE A.FIELD END)

You'll have to have one of these for each column.  This is where SQL
statements start to get big.

Joe