Executing Stored Procedure with Entity Framework - entity-framework

Question

We are currently developing an internal system, using the repository pattern and Entity Framework 5 as our ORM.
We have a bunch of stored procedures in our database that we call. Some of these procedures have similar parameter names. So when we make a call to execute the stored procedure, like so:
DbContext.Database.SqlQuery<ReturnType>(query, parameters)
The resulting enumerable fails on the second call to another procedure with a similar parameter name, saying:
ArgumentException was unhandled by user code: The SqlParameter is already contained by another SqlParameterCollection.
We have tried putting all SqlParameters into a collection which we loop through and null out all the items in the collection, but this fails as well....gloriously.
Is there a way to reach and manipulate the Object array in this stack trace?
at System.Data.SqlClient.SqlParameterCollection.Validate(Int32 index, Object value)
at System.Data.SqlClient.SqlParameterCollection.AddRange(Array values)
at System.Data.Objects.ObjectContext.CreateStoreCommand(String commandText, Object[] parameters)
at System.Data.Objects.ObjectContext.ExecuteStoreQueryInternal[TElement](String commandText, String entitySetName, MergeOption mergeOption, Object[] parameters)
at System.Data.Objects.ObjectContext.ExecuteStoreQuery[TElement](String commandText, Object[] parameters)
at System.Data.Entity.Internal.InternalContext.ExecuteSqlQuery[TElement](String sql, Object[] parameters)
at System.Data.Entity.Internal.InternalContext.ExecuteSqlQueryAsIEnumerable[TElement](String sql, Object[] parameters)
at System.Data.Entity.Internal.InternalContext.ExecuteSqlQuery(Type elementType, String sql, Object[] parameters)
at System.Data.Entity.Internal.InternalSqlNonSetQuery.GetEnumerator()
at System.Data.Entity.Internal.InternalSqlQuery1.GetEnumerator()
at System.Linq.Enumerable.First[TSource](IEnumerable1 source)

Answer 1

you can do something like that:
List<ReturnType> obj = DbContext.Database.SqlQuery<ReturnType>(query, parameters).ToList();
it will bind the variable obj, after that you can call the obj how many times you want without problem with sqlParameter.

Answer 2

I have not been able to resolve the issue, the command object in the built in SqlQuery method does not seem to clear the sql parameters, however I have a work around.
you can create your own command based on the current connection - but you will lose the ability to easily map out a return type.
public void CallStoredProc(string query, List<SqlParameter> parameters)
{
//this.Database.Connection (this = DBContext)
System.Data.Common.DbCommand cmd = this.Database.Connection.CreateCommand();
cmd.CommandText = query;
// add params
foreach (var item in parameters)
{
cmd.Parameters.Add(item);
}
// execute query (not differed)
var reader = cmd.ExecuteReader();
// attempt to read rows
if (reader.HasRows)
{
while (reader.Read())
{
// row level data
}
}
// cleanup
cmd.Parameters.Clear();
cmd.Dispose();
}

Answer 3

Are you able to make a copy of your parameters collection and each parameter that in rather than reusing the same instances of the parameters? Maybe have a helper method somewhere that automatically duplicates it for you.

Answer 4

Create Stored Procedure
ALTER PROCEDURE [dbo].[sp_GelUserContactDetails]
(
#Id INT=0,
#UserId int=0
)
AS
BEGIN
SELECT M.Id AS UserID, M.FirstName as Name,M.Designation,M.CompanyName FROM dbo.Flo_MemberShip M
WHERE ID=#Id
END
// Creating Stored Procedure that hold result of class MyContacts
public class MyContacts
{
public int UserID { get; set; }
public string Designation { get; set; }
public string Name { get; set; }
public string Organization { get; set; }
public string Image { get; set; }
public string RequestDate { get; set; }
public string IsContact { get; set; }
}
here I am creating a Entity that`s name is MyContacts. Here the MyContacts properties name must be the same as the returned column of the select statement of the Stored Procedure.
using (var context = new FLOEntities())
{
string query = "sp_GelUserContactDetails #Id,#UserId";
SqlParameter Id = new SqlParameter("#Id", selfId);
SqlParameter UserId = new SqlParameter("#UserId", userId);
obj = context.Database.SqlQuery<MyContacts>(query, Id, UserId).FirstOrDefault();
}
return obj;
click here

Answer 5

I found a solution, sort of a work around this issue. The stored proc call is made to instantiate a new DbContext that will be disposed after execution, like so.
IEnumerable<ReturnType> Results = null;
using (DbContext NewContext = new PrometheusEntities())
{
Results = NewContext.Database.SqlQuery<ReturnType>(query, parameters).ToList();
}
return Results;
I haven't experienced any issues since employing this method.