update p1 set p1.Previous_tot = p2.current_tot from Totals p1

join Totals p2 on p2.mid = p1.mid and p2.account = p1.accountand p2.sname = p1.sname and p2.mname = p1.mname and left(p2.Date,11) = left(getdate()-1,11)

where...

I think i figured it out using an update after the insert.

If I was going to insert these into a different table how would I go about getting the PrevTotal?

like this

col1 col2 ...

works great i just added isnull(T1.Total,0) - isnull(T2.Total,0) Diff.

thanks so much for the help.

it is a varChar. I need to look into the substring i guess.