Convert meine SQL in LINQ

Question

das ist mein Code, dass ich es schreibe, aber ich möchte LINQ verwenden, können Sie mir helfen, diesen Code zu LINQ zu konvertieren?

/// <summary> 
/// Stores the request in the PublisherRequests table and 
/// the selected categories in the PubReq_Categories table. 
/// </summary> 
/// <param name="UserId">The user's ID logged in.</param> 
/// <param name="Url">URL of the site that you want show the banner on it.</param> 
/// <param name="TypeId">The type id of the banner type you want to show.</param> 
/// <param name="CategoryIds">A set of category IDs depend on your banner.</param> 
/// <returns></returns> 

public static int PutRequest(string UserId,string Url,int TypeId,int[] CategoryIds) 
{ 
    int reqId; 

    using (SqlConnection cnn = new SqlConnection(ConfigurationManager.ConnectionStrings[0].ConnectionString)) 
    { 
     //Retrieves the last RequestId from database. 
     string selectLastReq = "SELECT TOP 1 RequestId FROM PublisherRequests WHERE UserId=" + 
      UserId.ToString() + "ORDER BY RequestId DESC"; 
     SqlCommand cmdSelect = new SqlCommand(selectLastReq, cnn); 

     //For inserting the new request in the database. 
     string insertRequest = string.Format("INSERT INTO PublisherRequests(" + 
      "RequestId, UserId,PageUrl, TypeId) VALUES ('{0}','{1}',{2})", 
      UserId, Url, TypeId); 
     SqlCommand cmdInsert = new SqlCommand(insertRequest, cnn); 

     //For inserting each category for the request on a new row. 
     string insertReqCat = string.Format("INSERT INTO PubReq_Categories(" + 
      "RequestId, CategoryId) VALUES (@ReqId,@CatId)"); 
     SqlCommand cmdInsertReqCat = new SqlCommand(insertReqCat, cnn); 
     cmdInsertReqCat.Parameters.Add("@ReqId", SqlDbType.Int); 
     cmdInsertReqCat.Parameters.Add("@CatId", SqlDbType.Int); 

     cnn.Open(); 

     //New request insertion. 
     cmdInsert.ExecuteNonQuery(); 

     //Retrieve last request number. 
     reqId = Convert.ToInt32(cmdSelect.ExecuteScalar()); 

     //Categories insertion. 
     cmdInsertReqCat.Parameters["@ReqId"].Value = reqId; 
     foreach (int catId in CategoryIds) 
     { 
      cmdInsertReqCat.Parameters["@CatId"].Value = catId; 
      cmdInsertReqCat.ExecuteNonQuery(); 
     } 
    } 

    return reqId; 
} 

Answer 1

Unter der Annahme, dass Sie den Designer verwenden, dass die RequestId Spalte automatisch generiert wird, müssen Sie eine Verbindung zwischen den beiden Klassen und die Klassen sind wie unten genannt, ich denke, das wird funktionieren.

using (var context = new DBDataContext()) 
{ 
    var request = new PublisherRequest 
        { 
        UserId = UserId, 
        PageUrl = Url, 
        TypeId = TypeId 
        }; 

    for (var categoryId in CategoryIds) 
    { 
     request.PubReqCategories.Add(new PubReqCategory 
             { 
              CategoryId = categoryId 
             }); 
    } 

    context.PublisherRequests.InsertOnSubmit(request); 
    context.SubmitChanges(); 
}