You can do a select in a SQL action, but you can only do something with the first row you are retrieving (by using %select to put them on the state record). It ignores all other rows (a bit like the SqlExec function in PeopleCode).

A do select allows you to also select a set of rows. You still put the values on the state record. But then App Engine will perform the other actions in the same step - per row found. It will loop as often as there are rows retrieved by your select statement.

So: selects are done with Do Select, data manipulation with the SQL action. Only if your select only retrieves one row you could use it in a SQL action.

Cheers,
Sam

Sam is exactly right. Think about a Do Select in the same way you think about a for, end-for in PeopleCode :)

You May also look at DO-UNTIL.

Thanks
Nitin