"Kraer, Joseph" <[EMAIL PROTECTED]> wrote on 11/30/2005 11:58:56 AM:
> I am trying to update a couple of rows in a table by doing the > following: > > update table > set column5 = number1 > where column 1 = number2 > and column1 = number3 > > but it is not working. I tried listing the conditions separated by > commas (where column 1 = number2, column1 = number3) and also didn't > work. What am I doing wrong? > > Thanks in advance, > > Joseph "Tito" Kraer > Business Systems Analyst > Taylor, Bean & Whitaker Mortgage Corp > UPDATE statements are evaluated on a row-by-row basis. What you actually told MySQL to do was to change any rows where column1 has BOTH values at the same time. Since one column in a single row cannot possibly have two values at once (not even SET columns because they do not have more than one set of values at a single time) this condition cannot possibly be met and the UPDATE will never happen. Make sense? You said: WHERE column1=number2 AND column1=number3 The AND is a logical comparator meaning that both comparisons must be true for the WHERE clause to be true and your desired UPDATE to occur. What I think you wanted to do is to UPDATE two rows. One row where column1=number2 and the other row where column1=number3. That is an OR situation not an AND situation: WHERE column1=number2 OR column1=number3 Another way to write that condition is with an IN clause : WHERE column1 IN (number2, number3) HTH! Shawn Green Database Administrator Unimin Corporation - Spruce Pine
