Nullable Table Valued Parameter in Stored Procedure - sql-server-2008

Question

I have this procedure
CREATE PROCEDURE dbo.spProcedure1
#intArray as dbo.intArray READONLY
AS
BEGIN
-- ...
END
which use user type as a parameter
CREATE TYPE dbo.IntArray AS TABLE (IntValue int NULL)
and I am calling the procedure from the C# ASP.NET MVC 4 project
// creating empty SQL #IntArray parameter
var emptyIntDataTable = new DataTable();
emptyIntDataTable.Columns.Add("IntValue");
// calling stored procedure
return Database.SqlQuery<int>(
#"spProcedure1 #p1",
new SqlParameter("p1", (object)Utils.ToDataTable(m.IntArray) ?? emptyIntDataTable)
).ToList();
// ToDataTable method which is returning null
public static DataTable ToDataTable<T>(this IList<T> data)
{
if (data == null)
return null;
... // code omitted because it is not working yet
}
the error which is throwed when calling stored procedure is
The table type parameter 'p1' must have a valid type name.
How to pass an empty table value?
Passing the list instead of datatable throw following error
var emptyIntDataTable = new List<int>;
No mapping exists from object type System.Collections.Generic.List`1[[System.Int32, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]] to a known managed provider native type.

Answer 1

In your code:
where it says:
return Database.SqlQuery<int>(
#"spProcedure1 #p1", new SqlParameter("p1",
(object)Utils.ToDataTable(m.IntArray) ?? emptyIntDataTable)
).ToList();
Change it to read:
return m.IntArray.Length > 0?
Database.SqlQuery<int>(#"spProcedure1 #p1",
new SqlParameter("p1",
(object)Utils.ToDataTable(m.IntArray))).ToList():
Database.SqlQuery<int>(#"spProcedure1")).ToList();
sample to show how to not pass table parameter
CREATE TYPE dbo.KeyIds]
AS TABLE(pkId int NOT NULL,
PRIMARY KEY CLUSTERED (pkId ASC)
WITH (IGNORE_DUP_KEY = OFF))
Go
-- ------------------------------
Create procedure testProc
#aIds dbo.keyIds readonly
as
Set NoCount On
if exists (select * from #aIds)
Select * from #aIds
else
Select 'No Aids passed in'
Go
-- ------------------------------
Exec dbo.testProc -- <--- Here I am NOT passing the #aids parameter
But, even though I am NOT passing the #aids parameter
it still works, and the subquery (select * from #aIds) still functions, and since it is an empty datatable the SP returns the empty message 'No Aids passed in'.
On the other hand, if you pass the parameter
Declare #MyIds dbo.keyIds
Insert #MyIds Values(1)
Insert #MyIds Values(2)
Insert #MyIds Values(3)
Insert #MyIds Values(4)
Insert #MyIds Values(5)
Exec dbo.testProc #MyIds -- <--- Here I AM passing the #aids parameter
it outputs the contents of the datatable parameter
C# code example...
public DataTable GetAccountTransactions(IEnumerable<int> accountIds)
{
const string procName = "FetchAccountTransactionData";
var acctIds = accountIds == null ?
new List<int>() : accountIds.ToList();
// -------------------------------------------------
var parms = DbParamList.Make();
// DbParamList is a List<IDbDataParameter>
// See here, ONLY ADD PARAMETER if list is NOT empty!
if (acctIds.Count > 0)
parms.AddSQLTableParm("aIds", acctIds);
try
{ // following constructs command obkect and calls SP
return Utilities.GetDataTable(schemaNm + "." +
procName, parms, copConn);
}
catch (SqlException dbX)
{
// Exception stuff
}
}
public class DbParamSortedList : SortedList<string,IDbDataParameter> { }

Answer 2

The alternative solution
prepare method for converting List<int> into dbo.IntArray type
public static DataTable IntArrayToDataTable(IEnumerable<int> ids)
{
if (ids == null)
return null;
DataTable table = new DataTable();
// datatable columns has to have same name as database type !
table.Columns.Add("IntValue", typeof(int));
foreach (int id in ids)
{
table.Rows.Add(id);
}
return table;
}
run sql stored procedure
var sqlParameters = new List<object>();
var parameter1 = Utils.IntArrayToDataTable(m.IntArray);
if (parameter1 != null)
sqlParameters.Add(new SqlParameter("intArray", parameter1)
// these variables are the key, without them it is not working
{
SqlDbType = SqlDbType.Structured,
TypeName = "dbo.IntArray"
});
else // parameter cannot be omitted !! even if all parameters are named !! otherwise parameter mismatch happens (in case of multiple parameters)
sqlParameters.Add(new SqlParameter("intArray", SqlDbType.Structured) { TypeName = "dbo.IntArray" });
var sqlQuery = "spProcedure1 #InArray";
return Database.SqlQuery<int>(sqlQuery, sqlParameters.ToArray()).ToList();