Issue passing comma delimited value to SelectCommand

Question

I have the following code in my .cs file:

SqlDataSource1.SelectParameters["LocID"].DefaultValue = "5957,5958";

I have the following code in my .aspx file

<asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:KuzSQL %>" OnSelecting="DataSourceSelecting"
    SelectCommand="Select ID, RoomNum from [dbo].[Mbiology] WHERE LocId IN (@LocId)" >
    <SelectParameters>
        <asp:Parameter Name="LocId" />
    </SelectParameters>        
</asp:SqlDataSource>

I get the following error:

Conversion failed when converting the nvarchar value '5957,5958' to data type int.

Note that LocId is of type Int.

Answer 1

Parameters are not just "inserted" into the SQL like you seem to think they are. It is tricky to try and pass a list of values into a query and use them in an IN clause.

Some options:

1. Pass the values as a string into a stored procedure that parses the string into a temp table, then use IN

2. Setup your command with several parameters ( LocId1 , LocId2 , etc.) and change your query to:

    Select ID, RoomNum from [dbo].[Mbiology] WHERE LocId IN (@LocId1, @LocId2, @LocId3, @LocId4, @LocId5, @LocId6, ...) 

3. Save your paramteres to a different table (maybe with a "sessionID" key) and pull from that in your IN clause.
4. Don't support multiple values in one query.

Answer 2

The SqlDataSource control does not support this type of operation, instead you have, at least, the following options:

1. Build the query in code-behind.

    protected void SomeEventHandler(object sender, EventArgs e) { // Create list of strings to hold ID values List<string> locIDs = new List<string>(); // Build list of actual string values foreach (var item in SomeControl.Items) { locIDs.Add(value); } // Build SELECT command SqlDataSource1.SelectCommand = String.Format("Select ID, RoomNum from [dbo].[Mbiology] WHERE LocId IN ({0})", String.Join(", ", productIDs.ToArray())); } 

2. Create a stored procedure and pass the list of ID values as a parameter.

Answer 3

You can create a procedure and create your sql query dynamically inside it. your procedure would be something like this -

create procedure p1_proc
    @val varchar(250)
as
begin
    declare @sql as varchar(500)
    set @sql = 'Select ID, RoomNum from [dbo].[Mbiology] WHERE LocId IN ('+@val+')'
    exec(@sql)
end

so your sqldatasource will call this procedure. something like this

<asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:KuzSQL %>" OnSelecting="DataSourceSelecting"
    SelectCommand="p1_proc" >
    <SelectParameters>
        <asp:Parameter Name="val" />
    </SelectParameters>        
</asp:SqlDataSource>

and you can pass the LocId s as a comma separated string.

SqlDataSource1.SelectParameters["val"].DefaultValue = "5957,5958";