Solutions for INSERT OR UPDATE on SQL Server

Question

Assume a table structure of MyTable(KEY, datafield1, datafield2...).

Often I want to either update an existing record, or insert a new record if it does

Answer 1

I usually do what several of the other posters have said with regard to checking for it existing first and then doing whatever the correct path is. One thing you should remember when doing this is that the execution plan cached by sql could be nonoptimal for one path or the other. I believe the best way to do this is to call two different stored procedures.

FirstSP:
If Exists
   Call SecondSP (UpdateProc)
Else
   Call ThirdSP (InsertProc)

Now, I don't follow my own advice very often, so take it with a grain of salt.