komal145 (9/26/2012)
...UPDATE TableC
SET step_desc= Tableb.StepDescription
FROM #MAX_STEPMAX_STEP WITH (NOLOCK)
JOIN TablebB WITH (NOLOCK) ON MAX_STEP.LoanNumber = b.LoanNumber
and MAx_step.Step=b.step
WHERE MAX_STEP.Row_ID = 2...
This is an unrestricted update. Every row in tableC will be updated to the same value of step_desc, because TableC isn't referenced in the FROM list. Since it's a trivial matter to convert a SELECT...FROM into an UPDATE...FROM, why don't you write it and post it here? What you want is a query which will return step_desc from TableC and Tableb.StepDescription.
For fast, accurate and documented assistance in answering your questions, please read this article.
Understanding and using APPLY, (I) and (II) Paul White
Hidden RBAR: Triangular Joins / The "Numbers" or "Tally" Table: What it is and how it replaces a loop Jeff Moden