Declare cursor based on dynamic query

Hi,

I am declaring the cursor based on a query which is generated dynamically. but it is not working

Declare @.tempSQL varchar(1000)

This query will be generated based on my other conditon and will be stored in a variable

set @.tempsql = 'select * from orders'

declare cursor test for @.tempsql

open test

This code is not working.

please suggest

Nitin

Hi

I am writing the code as below

Declare @.testSQl varchar(1000)

set @.testsql = 'select * from orders'

declare test1 cursor for @.testSQl

The declare statement is not working . My @.testsql will be generated at run time.

Help

Nitin

|||You can not use dynamic sql while opening the cursors..

it should be like this

Declare Test1 cursor for
Select * From Orders|||

You could add the cursor creation to your dynamic sql and then just call sp_executesql for the built up string. Something like...

DECLARE @.sql nvarchar(4000)

--Get beginning of cursor

SELECT @.sql = 'DECLARE c CURSOR FOR'

--Decision code for what query is built

SELECT @.sql = @.sql + 'SELECT * FROM orders'

--Remainder of cursor with specific columns from above query

SELECT @.sql = @.sql + 'OPEN c FETCH NEXT FROM c INTO ....'

--Execute the string we just built

EXEC sp_executesql @.sql

|||

I don't like to ever advocate the use of cursors, but you can do this using a global cursor, if you really must:

create procedure test
as
declare @.name nvarchar(128)
exec ('declare bob cursor global for select name from sys.objects')
open bob

fetch next from bob into @.name
select @.name as works
close bob
deallocate bob
go

test

|||

Hi,

I dont know for the moment how to declare a cursor on a query from a string.. I dont think its possible this way. An alternative is to find a solution other than using the cursor, else you'd lose development time in trying to find a solution.

If you cannot find a solution, try to explain the problem, someone will try help out, and also cursors generally tend to be less performant.

|||this is not possible. i agree with waaz|||

Instead of local cursor, you can create a Global cursor with dynamic sql, which is available beyond the scope the dynamic sql

like this

set @.sql='declare test cursor global for '+ @.tempsql

exec sp_executesql @.sql

open test

close test

|||You can use dynamic SQL to create a global cursor as shown in another reply in this thread. But what are you trying to do? Why do you need to use a cursor? And why do you need to use dynamic SQL? Both have performance implications. And dynamic SQL has serious security implications that can compromise your database system and/or network. You will have to use techniques (both in the database and client-side depending on how you call your SP) that avoid SQL injection to protect your database and network from malicious users. Apart from these problems, dynamic SQL requires more maintainence because you have to grant more permissions to end users since checks are deferred to run-time unlike SPs with static SQL statements. So it is easy to create a cursor dynamically but that is not the right thing to do in majority of the cases.|||

Also, try not to ask the same question twice. This question was also answered in another thread. I have merged the threads into one.

|||

hey whitney,

i got the same problem of dynamic query with cursors..

You gave the alternative but i got the big cursor and its difficult for me to put the entire stuff in string.

Because it gets difficult to maintain for me.

Any help or comment regarding this will be appreciated.

Thanks a ton!!

dromyl@.hotmail.com