T-SQL loop over query results - tsql

Question

I run a query select #id=table.id from table and I need to loop over the results so I can exec a store procedure for each row exec stored_proc #varName=#id,#otherVarName='test'
How can I do this in a T-SQL script?

Answer 1

You could use a CURSOR in this case:
DECLARE #id INT
DECLARE #name NVARCHAR(100)
DECLARE #getid CURSOR
SET #getid = CURSOR FOR
SELECT table.id,
table.name
FROM table
OPEN #getid
FETCH NEXT
FROM #getid INTO #id, #name
WHILE ##FETCH_STATUS = 0
BEGIN
EXEC stored_proc #varName=#id, #otherVarName='test', #varForName=#name
FETCH NEXT
FROM #getid INTO #id, #name
END
CLOSE #getid
DEALLOCATE #getid
Modified to show multiple parameters from the table.

Answer 2

You could do something like this:
create procedure test
as
BEGIN
create table #ids
(
rn int,
id int
)
insert into #ids (rn, id)
select distinct row_number() over(order by id) as rn, id
from table
declare #id int
declare #totalrows int = (select count(*) from #ids)
declare #currentrow int = 0
while #currentrow < #totalrows
begin
set #id = (select id from #ids where rn = #currentrow + 1)
exec stored_proc #varName=#id, #otherVarName='test'
set #currentrow = #currentrow +1
end
END

Answer 3

My prefer solution is Microsoft KB 111401 http://support.microsoft.com/kb/111401.
The link refers to 3 examples:
This article describes various methods that you can use to simulate a cursor-like FETCH-NEXT logic in a stored procedure, trigger, or Transact-SQL batch.
/*********** example 1 ***********/
declare #au_id char( 11 )
set rowcount 0
select * into #mytemp from authors
set rowcount 1
select #au_id = au_id from #mytemp
while ##rowcount <> 0
begin
set rowcount 0
select * from #mytemp where au_id = #au_id
delete #mytemp where au_id = #au_id
set rowcount 1
select #au_id = au_id from #mytemp
end
set rowcount 0
/********** example 2 **********/
declare #au_id char( 11 )
select #au_id = min( au_id ) from authors
while #au_id is not null
begin
select * from authors where au_id = #au_id
select #au_id = min( au_id ) from authors where au_id > #au_id
end
/********** example 3 **********/
set rowcount 0
select NULL mykey, * into #mytemp from authors
set rowcount 1
update #mytemp set mykey = 1
while ##rowcount > 0
begin
set rowcount 0
select * from #mytemp where mykey = 1
delete #mytemp where mykey = 1
set rowcount 1
update #mytemp set mykey = 1
end
set rowcount 0

Answer 4

DECLARE #id INT
DECLARE #name NVARCHAR(100)
DECLARE #getid CURSOR
SET #getid = CURSOR FOR
SELECT table.id,
table.name
FROM table
WHILE 1=1
BEGIN
FETCH NEXT
FROM #getid INTO #id, #name
IF ##FETCH_STATUS < 0 BREAK
EXEC stored_proc #varName=#id, #otherVarName='test', #varForName=#name
END
CLOSE #getid
DEALLOCATE #getid

Answer 5

try this:
declare #i tinyint = 0,
#count tinyint,
#id int,
#name varchar(max)
select #count = count(*) from table
while (#i < #count)
begin
select #id = id, #name = name from table
order by nr asc offset #i rows fetch next 1 rows only
exec stored_proc #varName = #id, #otherVarName = 'test', #varForName = #name
set #i = #i + 1
end

Answer 6

DECLARE #id INT
DECLARE #filename NVARCHAR(100)
DECLARE #getid CURSOR
SET #getid = CURSOR FOR
SELECT top 3 id,
filename
FROM table
OPEN #getid
WHILE 1=1
BEGIN
FETCH NEXT
FROM #getid INTO #id, #filename
IF ##FETCH_STATUS < 0 BREAK
print #id
END
CLOSE #getid
DEALLOCATE #getid