Call stored procedure from Entity Framework dynamically

Question

Given a name, I need to check to see if a stored procedure with that name exists in our EDMX and then run it with its parameters.

The sproc to be called is found by a context.Database.SqlQuery, and the parameters for the query are found by running a known sproc via context.GetQueryParameters(string QueryName).

I'm left with a sproc name, and it's SQL parameter names and types.

Thank you in advance for your help! This has been killing me...

Answer 1

It's hard to guess exactly what you are using this for but based on your use of GetQueryParameters as a proc name, I'm guessing this if for different queries/searches.

If these all return the same type (a search result) and the reason you want to do this in EF is that strong typing, you could do something like the following: (Example uses a test context in EF5 and LinqPad)

using (var context = new TestEntities())
{
    string procname = "GetPrograms";
    // context has method GetPrograms(int? id)

    // Method1 - use the method on the context
    // This won't work dynamically
    IEnumerable<GetPrograms_Result> result1 = context.GetPrograms(4);
    result1.Dump("Method1");

    // Method2 - use reflection to get and use the method on the context
    // Building your parameters needs to be in the order they are on the method
    // This gets you an IEnumerable, but not a strongly typed one

    MethodInfo method = context.GetType().GetMethod(procname);
    method.GetParameters();
    List<object> parameters = new List<object>();
    parameters.Add(4);

    IEnumerable result2 = (IEnumerable) method.Invoke(context,parameters.ToArray());
    result2.Dump("Method2");

    // Method3 - make a SqlQuery call on a common return type, passing a dynamic list
    // of SqlParameters.  This return type can be but dows not need to be an Entity type

    var argList = new List<SqlParameter>();
    argList.Add(new SqlParameter("@id",4));

    object[] prm = argList.ToArray();
    var csv = String.Join(",",argList.Select (l => l.ParameterName));

    IEnumerable<GetPrograms_Result> result3 = context.Database.SqlQuery<GetPrograms_Result>("exec " + procname + " " + csv ,prm);
    result3.Dump("Method3");
}