Loop for each row

Question

I have two tables with FOREIGN KEY([Table_ID])

Columns

ID       Table_ID       ActiveFlag
1        1              0
2        2              1
3        1              1
4        3              0

Sys_Tables

Table_ID       Name
1              Request
2              Plan
3              Contecst

I'm writing a stored procedure that returns any column for each table.

Example Output for values ​​above

--first output table
ID       Table_ID       ActiveFlag
1        1              0
3        1              1
--second output table
ID       Table_ID       ActiveFlag
2        2              1
--third output table
ID       Table_ID       ActiveFlag
4        3              0

My idea is this

Select c.*             
from Ccolumns c
     inner join Sys_tables t
    on t.Table_ID = c.Table_ID and t.Table_ID = @Parameter

My problem, i do't know how to make a loop for each row. I need the best way. Example i can use following loop:

DECLARE @i int = 0
DECLARE @count int;
select @count = count(t.Table_ID)
from Sys_tables t
     WHILE @i < @count BEGIN
    SET @i = @i + 1
--DO ABOVE SELECT   
END

But this is not entirely correct. Example my Sys_tables such data may be

Table_ID       Name
1              Request
102            Plan
1001           Contecst

Do You have any idea?

Answer 1

There are couple ways you can achieve that: loops and cursors, but first of all you need to know that it's a bad idea: either are very slow, anyway, here's some kind of loop sample:

declare @row_ids table (
    id INT IDENTITY (1, 1),
    rid INT
); 
insert into @row_ids (rid) select someIdField from SomeTable

declare @cnt INT = @@ROWCOUNT
declare @currentRow INT = 1

WHILE (@currentRow <= @cnt)
BEGIN
    SELECT rid FROM @row_ids WHERE id = @currentRow
    SET @currentRow = @currentRow + 1
END

Answer 2

I guess you're using SQL Server, right?

Then, you can use a CURSOR as here: How to write a cursor inside a stored procedure in SQL Server 2008