Iterate through a temp table - sql

Question

I did try looping through a temp table, but of no use end up with so many errors only.
Please help me on how can I work this one out..
My need is like :
I need to fetch an ID column from a table, and store it in one temp table.
Then iterate through each ID, and execute a stored procedure which takes that ID as an parameter.
Insert the return value (= one column) of that stored procedure in another table.
Please guide me on how to do this.
I did search a lot..and got confused with cursor and set based join.

Answer 1

IMHO in your case you don't need a temp table.
Let's say you have following two tables. First is source table and the other is destination table.
CREATE TABLE mytable(id INT IDENTITY PRIMARY KEY, col1 nvarchar(10));
CREATE TABLE mytable2(id INT, value INT);
mytable has following sample data in it:
id col1
----------------
1 row1
2 row2
3 row3
4 row4
And you have some SP that calculates something based on id, something like this
CREATE PROCEDURE getValue (#id INT, #value INT OUT)
AS
SET NOCOUNT ON;
SET #value = #id * 2;
Then you can create an SP that will do the job like this
CREATE PROCEDURE proccessData
AS
SET NOCOUNT ON;
DECLARE #id INT, #value INT;
DECLARE id_cursor CURSOR FOR
SELECT id FROM mytable WHERE id > 1 AND id < 4;
OPEN id_cursor;
FETCH NEXT FROM id_cursor INTO #id;
WHILE ##FETCH_STATUS = 0
BEGIN
EXEC getValue #id, #value OUTPUT;
INSERT INTO mytable2 VALUES(#id, #value);
-- Or use update if you already have id's in mytable2
-- UPDATE mytable2 SET value = #value WHERE id = #id;
FETCH NEXT FROM id_cursor INTO #id;
END
CLOSE id_cursor;
DEALLOCATE id_cursor;
After you call that SP
EXEC proccessData
you'll get in mytable2
id value
----------- -----------
2 4
3 6
And here is working sqlfiddle