UPDATE dbo.Table1
SET colA = CASE ColC WHEN 'Yes' THEN (SELECT col1 FROM Table2 WHERE col10 = 'A') ELSE NULL END
,SET colB = CASE ColC WHEN 'Yes' THEN (SELECT col1 FROM Table2 WHERE col10 = 'A') ELSE NULL END
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability