Pass parameter to In query in C# and SQL Server 2005

Question

I need to pass this string parameter value via C# application to a SQL Server query:

'foo', 'bar'

This is the query in the code-behind:

sql = @String.Format(" SELECT * FROM ");
sql += String.Format("  [dbo].[PDTM] ");
sql += String.Format(" WHERE ");
sql += String.Format(" PDTM IN (@param1); ");

command.Parameters.AddWithValue("param1", txtPDTM.Text.ToString());

But this does not work yet because the output is empty.

Then I try to change the SQL query to:

sql = @String.Format(" SELECT * FROM ");
sql += String.Format("  [dbo].[PDTM] ");
sql += String.Format(" WHERE ");
sql += String.Format(" PDTM IN (" + txtPDTM.Text.ToString() + "); ");

And this works.

So what is the correct way to pass parameter to IN query in C#?

Answer 1

This is a function fn_split_string which splits a string:

ALTER function dbo.fn_split_string(@str nvarchar(1000),@sep nvarchar(1))
returns @tab_split  table (id int identity(1,1),str nvarchar(1000) )  
as  

begin  
declare @str1 as nvarchar(1000)  
declare @istr as nvarchar(1000)  
declare @i as integer  
set @str1=@str  
set @i=2  
while @i>0 
begin  
set @i=charindex(@sep,@str1,1)  
if @i>0  
begin  
set @istr=substring(@str1,1,@i-1)  
insert into @tab_split(str) values(@istr)  
set @str1=substring(@str1,@i+1,len(@str1))  
end  
end  
insert into @tab_split(str) values(@str1)  
return   
end

And running the function as follows :

SELECT * FROM dbo.fn_split_string ('foo, bar',',');

The output is :

1   foo
2   bar

It would be something such as :

SELECT * FROM dbo.PDTM WHERE PDTM IN (SELECT str FROM dbo.fn_split_string(@param1,','))

As pointed already the next one is to pass directly a list of string to your SQL statement.

Hope this can help you.

Best regards,