TSQL Statement IN - sql

Question

I am having a small problem with the IN SQL statement. I was just wondering if anyone could help me?
#Ids = "1,2,3,4,5"
SELECT * FROM Nav WHERE CONVERT(VARCHAR,NavigationID) IN (CONVERT(VARCHAR,#Ids))
This is coming back with the error below, I am sure this is pretty simple!
Conversion failed when converting the varchar value '1,' to data type int.

Answer 1

The SQL IN clause does not accept a single variable to represent a list of values -- no database does, without using dynamic SQL. Otherwise, you could use a Table Valued Function (SQL Server 2000+) to pull the values out of the list & return them as a table that you can join against.
Dynamic SQL example:
EXEC('SELECT *
FROM Nav
WHERE NavigationID IN ('+ #Ids +')')
I recommend reading The curse and blessings of dynamic SQL before using dynamic SQL on SQL Server.

Answer 2

Jason:
First create a function like this
Create FUNCTION [dbo].[ftDelimitedAsTable](#dlm char, #string varchar(8000))
RETURNS
--------------------------------------------------------------------------*/
/*------------------------------------------------------------------------
declare #dlm char, #string varchar(1000)
set #dlm=','; set #string='t1,t2,t3';
-- tHIS FUNCION RETUNRS IN THE ASCENDING ORDER
-- 19TH Apr 06
------------------------------------------------------------------------*/
--declare
#table_var TABLE
(id int identity(1,1),
r varchar(1000)
)
AS
BEGIN
declare #n int,#i int
set #n=dbo.fnCountChars(#dlm,#string)+1
SET #I =1
while #I <= #N
begin
insert #table_var
select dbo.fsDelimitedString(#dlm,#string,#i)
set #I= #I+1
end
if #n =1 insert #TABLE_VAR VALUES(#STRING)
delete from #table_var where r=''
return
END
And then
set quoted_identifier off
declare #ids varchar(max)
select #Ids = "1,2,3,4,5"
declare #nav table ( navigationid int identity(1,1),theother bigint)
insert #nav(theother) select 10 union select 11 union select 15
SELECT * FROM #Nav WHERE CONVERT(VARCHAR,NavigationID) IN (select id from dbo.ftDelimitedAsTable(',',#Ids))
select * from dbo.ftDelimitedAsTable(',',#Ids)

Answer 3

What you're doing is not possible with the SQL IN statement. You cannot pass a string to it and expect that string to be parsed. IN is for specific, hard-coded values.

Answer 4

There are two ways to do what you want to do here.
One is to create a 'dynamic sql' query and execute it, after substituting in your IN list.
DECLARE #query varchar(max);
SET #query = 'SELECT * FROM Nav WHERE CONVERT(VARCHAR,NavigationID) IN (' + #Ids + ')'
exec (#query)
This can have performance impacts and other complications. Generally I'd try to avoid it.
The other method is to use a User Defined Function (UDF) to split the string into its component parts and then query against that.
There's a post detailing how to create that function here
Once the function exists, it's trivial to join onto it
SELECT * FROM Nav
CROSS APPLY dbo.StringSplit(#Ids) a
WHERE a.s = CONVERT(varchar, Nav.NavigationId)
NB- the 'a.s' field reference is based on the linked function, which stores the split value in a column named 's'. This may differ based on the implementation of your string split function
This is nice because it uses a set based approach to the query rather than an IN subquery, but a CROSS JOIN may be a little complex for the moment, so if you want to maintain the IN syntax then the following should work:
SELECT * FROM Nav
WHERE Nav.NavigationId IN
(SELECT CONVERT(int, a.s) AS Value
FROM dbo.StringSplit(#Ids) a