How to execute a stored procedure inside a select query

Thanks @twoleggedhorse.

Here is the solution.

1. First we created a function

   CREATE FUNCTION GetAIntFromStoredProc(@parm Nvarchar(50)) RETURNS INTEGER
   
   AS
   BEGIN
      DECLARE @id INTEGER
   
      set @id= (select TOP(1) id From tbl where col=@parm)
   
      RETURN @id
   END
   

2. then we do the select query

   Select col1, col2, col3,
   GetAIntFromStoredProc(T.col1) As col4
   From Tbl as T
   Where col2=@parm
   

Functions are easy to call inside a select loop, but they don't let you run inserts, updates, deletes, etc. They are only useful for query operations. You need a stored procedure to manipulate the data.

So, the real answer to this question is that you must iterate through the results of a select statement via a "cursor" and call the procedure from within that loop. Here's an example:

DECLARE @myId int;
DECLARE @myName nvarchar(60);
DECLARE myCursor CURSOR FORWARD_ONLY FOR
    SELECT Id, Name FROM SomeTable;
OPEN myCursor;
FETCH NEXT FROM myCursor INTO @myId, @myName;
WHILE @@FETCH_STATUS = 0 BEGIN
    EXECUTE dbo.myCustomProcedure @myId, @myName;
    FETCH NEXT FROM myCursor INTO @myId, @myName;
END;
CLOSE myCursor;
DEALLOCATE myCursor;

Note that @@FETCH_STATUS is a standard variable which gets updated for you. The rest of the object names here are custom.