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C#: Dapper with JsonConvert.SerializeObject() not working properly

I'm new to Newtonsoft.Json and Dapper.
I am executing an SQL query, and using the query's result I'm converting it to a JSON string to try to make it look like this:
{ "Orders" : [{"OrderID":10248, "Quantity":12}, {"OrderID":10343, "Quantity":4}, ...etc...]}
However when I run my C# code, my output looks completely different along with some unexpected additions:
[
{
"JSON_F52E2B61-18A1-11d1-B105-00805F49916B": "{\"Orders\":[{\"OrderID\":10248,\"Quantity\":12},{\"OrderID\":10248,\"Quantity\":10}{\"OrderID\":10271,\"Quantity\":24},{\"OrderID\":10272,\"Quantity\":6},{\"OrderID\":1027"
},
{
"JSON_F52E2B61-18A1-11d1-B105-00805F49916B": "2,\"Quantity\":40},{\"OrderID\":10272,\"Quantity\":24}, ...etc... ]
As you can see I do not understand why it is adding the additional "JSON_F52E2B61-18A1-11d1-B105-00805F49916B". How do I remove these? How do I change my code to make it look like my desired output json string?
This is my code. I also made a fiddle with the incorrect output I'm getting https://dotnetfiddle.net/uWV6vs :
// Dapper Plus
// Doc: https://dapper-tutorial.net/query
// #nuget: Dapper -Version 1.60.6
using Newtonsoft.Json;
using Dapper;
using System;
using System.Data.SqlClient;
public class Program
{
public class OrderDetail
{
public int OrderDetailID { get; set; }
public int OrderID { get; set; }
public int ProductID { get; set; }
public int Quantity { get; set; }
}
public static void Main()
{
string sql = "SELECT OrderID, Quantity FROM OrderDetails FOR JSON PATH, root ('Orders'), INCLUDE_NULL_VALUES";
using (var connection = new SqlConnection(FiddleHelper.GetConnectionStringSqlServerW3Schools()))
{
dynamic orderDetail = connection.Query(sql);
//edit: the answer is to use connection.Query<string>, orderDetail[0]
orderDetail = JsonConvert.SerializeObject(orderDetail,Formatting.Indented);
Console.WriteLine(orderDetail);
}
}
}

I believe you don't need to request JSON from SQL, Dapper will parse results to the objects automatically
Removing "FOR JSON PATH, root ('Orders'), INCLUDE_NULL_VALUES" should help
string sql = "SELECT OrderID, Quantity FROM OrderDetails";
UPDATE:
sorry, keep updating the answer. This one gives you objects with the right structure and no extra backslashes
using Newtonsoft.Json;
using Dapper;
using System;
using System.Data.SqlClient;
using System.Collections.Generic;
public class Program
{
public class OrderDetail
{
public int OrderDetailID { get; set; }
public int OrderID { get; set; }
public int ProductID { get; set; }
public int Quantity { get; set; }
}
public class Result
{
public IEnumerable<OrderDetail> Orders { get; set; }
}
public static void Main()
{
string sql = "SELECT OrderID, Quantity FROM OrderDetails";
using (var connection = new SqlConnection(FiddleHelper.GetConnectionStringSqlServerW3Schools()))
{
var orderDetail = connection.Query<OrderDetail>(sql);
var str = JsonConvert.SerializeObject(new Result { Orders = orderDetail },Formatting.Indented);
Console.WriteLine(str);
}
}
}

Loading instance of entity takes more than 1 second

I ran into one interesting thing in EF. If we get child entity using base entity, loading entities takes more time. My model looks like this:
public abstract class BaseDocument
{
public Guid Id { get; set; }
public string Name { get; set; }
}
public abstract class ComplexDocument : BaseDocument
{
public string AuthorName { get; set; }
}
public abstract class SimpleDocument : BaseDocument
{
public int Level { get; set; }
}
public abstract class OfficeDocument : ComplexDocument
{
public string OfficeName { get; set; }
}
public abstract class ClassDocument : SimpleDocument
{
public string HeadName { get; set; }
}
public class WordDocument : OfficeDocument
{
public int PagesCount { get; set; }
}
public class ExcelDocument : OfficeDocument
{
public int SheetsCount { get; set; }
}
public class TextDocument : ClassDocument
{
public int LinesCount { get; set; }
}
I am using the TPT approach. Here is the inheritance tree
Here is my context class:
public class Context : DbContext
{
public Context() : base(#"Server=(localdb)\MSSQLLocalDB;Database=EFSIX;Trusted_Connection=True;")
{
Database.CreateIfNotExists();
}
public DbSet<BaseDocument> BaseDocuments { get; set; }
public DbSet<ComplexDocument> ComplexDocuments { get; set; }
public DbSet<SimpleDocument> SimpleDocuments { get; set; }
public DbSet<OfficeDocument> OfficeDocuments { get; set; }
public DbSet<ClassDocument> ClassDocuments { get; set; }
public DbSet<ExcelDocument> ExcelDocuments { get; set; }
public DbSet<WordDocument> WordDocuments { get; set; }
public DbSet<TextDocument> TextDocuments { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<BaseDocument>().ToTable("BaseDocuments");
modelBuilder.Entity<ComplexDocument>().ToTable("ComplexDocuments");
modelBuilder.Entity<SimpleDocument>().ToTable("SimpleDocuments");
modelBuilder.Entity<OfficeDocument>().ToTable("OfficeDocuments");
modelBuilder.Entity<ExcelDocument>().ToTable("ExcelDocuments");
modelBuilder.Entity<WordDocument>().ToTable("WordDocuments");
modelBuilder.Entity<ClassDocument>().ToTable("ClassDocuments");
modelBuilder.Entity<TextDocument>().ToTable("TextDocuments");
}
public IQueryable<T> GetEntities<T>() where T : class
{
return Set<T>();
}
}
I'm creating some data:
static void CreateTestData()
{
using (Context context = new Context())
{
for (int i = 0; i < 20; i++)
{
ExcelDocument excel = new ExcelDocument()
{
Id = Guid.NewGuid(),
AuthorName = $"ExcelAuthor{i}",
Name = $"Excel{i}",
OfficeName = $"ExcelOffice{i}",
SheetsCount = (i + 1) * 10
};
context.ExcelDocuments.Add(excel);
WordDocument word = new WordDocument()
{
Id = Guid.NewGuid(),
AuthorName = $"WordAuthor{i}",
Name = $"Word{i}",
OfficeName = $"WordOffice{i}",
PagesCount = (i + 2) * 10
};
context.WordDocuments.Add(word);
TextDocument text = new TextDocument()
{
Id = Guid.NewGuid(),
Name = $"Text{i}",
LinesCount = (i + 3) * 10,
HeadName = $"Head{i}",
Level = i + 5
};
context.TextDocuments.Add(text);
}
context.SaveChanges();
}
}
I made some two methods for getting WordDocument from db. One of them using BaseDocument and another one using WordDocument. Both returns 20 instances of WordDocument:
static long ReadBaseDoc()
{
using (Context context = new Context())
{
var words= context.GetEntities<BaseDocument>().Where(e => e.Name.StartsWith("Word"));
Stopwatch stopwatch = Stopwatch.StartNew();
var instacnes = excel.ToList();
stopwatch.Stop();
return stopwatch.ElapsedMilliseconds;
}
}
static long ReadWordDoc()
{
using (Context context = new Context())
{
var words = context.GetEntities<WordDocument>().Where(e => e.Name.StartsWith("Word"));
Stopwatch stopwatch = Stopwatch.StartNew();
var instacnes = words.ToList();
stopwatch.Stop();
return stopwatch.ElapsedMilliseconds;
}
}
I tested moth method separately, several times, in average method ReadWordDoc takes 25ms and method ReadBaseDoc takes 52ms (instances are the same ).
It's not too big problem now, but when we have complex inheritance it takes more than 1 second. I created 10 classes and inherited from BaseDocument. After that I executed ReadBaseDoc and ReadWordDoc methods. ReadWordDoc took 25ms and ReadBaseDoc took 1023ms. Instances are the same, why ReadBaseDoc takes more time? What is the better way to avoid this kind of problems in EF?

Take a look here. There are ways to make EF faster, but in those complex scenarios ORM just creates more problems than it solves.
One way in your case would be to try to change the inheritance to TablePerType, MAYBE it will be a little bit faster.
Other way would be to locate the slow request and use Dapper for them - it will be much faster.
Last way would be to create a Repository with live cache that loads the full database into memory and keeps it up to date - this should be a singleton in an app. If you have more than one app using the same database, you need to hookup data change triggers.
In general, I would say for slow (and relatively simple) queries like yours, use Dapper + AutoMapper. Keep EF so that your database stays synchronized with your classes, but do not rely on it for queries.
If you really want to stick to ORM, I think you need to switch nHibernate. Haven't try it myself, but form what I read, it is superior in almost every possible way, that includes performance and startup time.

Entity Framework 5 Won't Fetch Relationships With Include()

I am quite certain that questions like this have been answered a number of times before, but I can't get any of the suggestions to work.
I am building a MVC 4 application with Entity Framework 5, where the entities were generated from existing tables. I have entity classes that look like this:
namespace RebuildingModel
{
using System;
using System.Collections.Generic;
public partial class StandardCodeTable
{
public StandardCodeTable()
{
this.StandardCodeTableTexts = new HashSet<StandardCodeTableText>();
}
public int TableCode { get; set; }
public string RefTableName { get; set; }
public virtual ICollection<StandardCodeTableText> StandardCodeTableTexts { get; set; }
}
}
namespace RebuildingModel
{
using System;
using System.Collections.Generic;
public partial class StandardCodeTableText
{
public int TableCode { get; set; }
public string LanguageCode { get; set; }
public string TextVal { get; set; }
public virtual StandardCodeTable StandardCodeTable { get; set; }
}
}
namespace RebuildingSite.Models
{
public class CodeTableJoined
{
public int TableCode { get; set; }
public string ReferenceTableName { get; set; }
public string LanguageCode { get; set; }
public string TextValue { get; set; }
}
}
I have a DAO that looks like this:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace RebuildingModel.Dao
{
public class CodeTableDao
{
public CodeTableDao() { }
public ISet<StandardCodeTableText> GetCode(string refTableName)
{
HashSet<StandardCodeTableText> codes = new HashSet<StandardCodeTableText>();
using (var db = new RebuildingTogetherEntities())
{
db.StandardCodeTableTexts.Include("StandardCodeTables");
var query = from c in db.StandardCodeTableTexts
where c.StandardCodeTable.RefTableName == refTableName
orderby c.TableCode
select c;
foreach (var item in query)
{
codes.Add(item);
}
}
return codes;
}
}
I have a controller that looks like this:
namespace RebuildingSite.Controllers
{
public class CodeTableController : Controller
{
public ActionResult Index(string refTableName)
{
CodeTableDao dao = new CodeTableDao();
ICollection<StandardCodeTableText> codes = dao.GetCode(refTableName);
HashSet<CodeTableJoined> joins = new HashSet<CodeTableJoined>();
foreach (var code in codes)
{
CodeTableJoined join = new CodeTableJoined();
join.TableCode = code.TableCode;
join.LanguageCode = code.LanguageCode;
join.TextValue = code.TextVal;
join.ReferenceTableName = code.StandardCodeTable.RefTableName;
joins.Add(join);
}
ISet<string> refTableNames = dao.GetReferenceTables();
ViewBag.RefTableNames = refTableNames;
return View(joins);
}
}
}
When I run the view attached to the controller, an ObjectDisposedException is thrown at this line, where the relationship is used:
join.ReferenceTableName = code.StandardCodeTable.RefTableName;
This has to be something simple. What am I doing wrong? I have tried adding that Include() call in from the context in many different places, even multiple times.
I've also tried adding an explicit join in the Linq query. I can't get EF to fetch that relationship.

Copying my comment to an answer - Put the include be in the actual query
var query = from c in
db.StandardCodeTableTexts.include("StandardCodeTables"). where
c.StandardCodeTable.RefTableName == refTableName orderby c.TableCode
select c;

Does not contain a constructor that takes 2 arguments

I'm not sure what is occurring here. The model was auto generated from the database and I can't see anything obvious (mind you it is 2.30am UK time at the moment so maybe I'm half asleep). I am getting the error: ActiveCitizenSystemMimic.Models.ActiveCitizenProperties does not contain a constructor that takes 2 arguments.
Model:
namespace ActiveCitizenSystemMimic.Models
{
using System;
using System.Collections.Generic;
public partial class ActiveCitizenProperties
{
public int FK_ActiveCitizen { get; set; }
public int FK_PropertyType { get; set; }
}
}
Controller:
List<ActiveCitizenProperties> activeCitizenProperties = new List<ActiveCitizenProperties>();
activeCitizenProperties.Add(new ActiveCitizenProperties(1, 2));

You may replace your code to:
List<ActiveCitizenProperties> activeCitizenProperties = new List<ActiveCitizenProperties>();
activeCitizenProperties.Add(new ActiveCitizenProperties(){ FK_ActiveCitizen = 1, FK_PropertyType = 2 });
Your "auto-generated" class obviously doesn't contain a constructor that takes 2 arguments. If it has, it would be like this:
namespace ActiveCitizenSystemMimic.Models
{
using System;
using System.Collections.Generic;
public partial class ActiveCitizenProperties
{
public int FK_ActiveCitizen { get; set; }
public int FK_PropertyType { get; set; }
public ActiveCitizenProperties(int a, int b)
{
this.FK_ActiveCitizen = a;
this.FK_PropertyType = b;
}
}
}

The errors means what it does say: ActiveCitizenProperties constructor doesn't accept two parameters. In the code given no constructor defined in the class at all.
You may use though:
new ActiveCitizenProperties { FK_ActiveCitizen = 1, FK_PropertyType = 2 };

DataBinding to a WinForm

I have a form (CustomerInfoForm) with 10 TextBoxes. The default Text property for each of the TextBoxes is defined at design-time. A subclass CustomerInfoForm.CustomerInfo contains properties to hold the data entered in the form. The subclass containing the data will be serialized to XML.
In the automatically generated form code, each of the text boxes has a line of code to bind the datasource to the text box
this.customerInfoBindingSource = new System.Windows.Forms.BindingSource(this.components);
Code automatically generated by the C# ide for each text box:
this.txtCustomer.DataBindings.Add(new System.Windows.Forms.Binding("Text", this.customerInfoForm_CustomerInfoBindingSource, "CustomerName", true));
this.txtCustomer.Location = new System.Drawing.Point(60, 23);
this.txtCustomer.Name = "txtCustomer";
this.txtCustomer.Size = new System.Drawing.Size(257, 20);
this.txtCustomer.TabIndex = 0;
this.txtCustomer.Text = "CustomerName";
(I noticed that the Text property isn't set until after the DataBinding) in the IDE generated code.
When I run the project, the form is displayed with the default values in the TextBoxes. However when the SaveButton is pressed to serialize the properties in the MyForm.CustomerInfo subclass, they are all null. Since these values will only be changed from the form I was hoping that I didn't have to implement the interface INotifyPropertyChanged.
Am I missing something basic or simple?
The code for the form including the serialization of the data is attached below
using System;
using System.Windows.Forms;
using System.Xml.Serialization;
using System.IO;
using System.Runtime.Serialization;
namespace SimpleCustomerInfo
{
// You must apply a DataContractAttribute or SerializableAttribute
// to a class to have it serialized by the DataContractSerializer.
public partial class CustomerInfoForm : Form
{
CustomerInfo ci = new CustomerInfo();
public CustomerInfoForm()
{
InitializeComponent();
}
private void btnSave_Click(object sender, EventArgs e)
{
DataContractSerializer serializer = new DataContractSerializer(typeof(CustomerInfo));
FileStream writer = new FileStream(#"C:\Users\Me\temp\testme.xml", FileMode.Create);
serializer.WriteObject(writer,ci);
writer.Close();
}
[DataContract(Name = "Customer", Namespace = "net.ElectronicCanvas")]
public class CustomerInfo
{
[DataMember]
public string CustomerName { get; set; }
[DataMember]
public PhoneInfo PhonePrimary { get; set; }
[DataMember]
public PhoneInfo PhoneDays { get; set; }
[DataMember]
public PhoneInfo PhoneEvening { get; set; }
}
public class PhoneInfo
{
public string number { get; set; }
public string type { get; set; }
public bool textOk { get; set; }
}
}
}
EDIT -- For others that may happen upon this question
using System;
using System.Windows.Forms;
using System.Xml.Serialization;
using System.IO;
using System.Runtime.Serialization;
namespace SimpleCustomerInfo
{
public partial class CustomerInfoForm : Form
{
CustomerInfo ci;
public CustomerInfoForm()
{
InitializeComponent();
ci = new CustomerInfo();
ci.CustomerName = "My Customer Name";
ci.PhoneDays.number = "888-888-8888";
customerInfoForm_CustomerInfoBindingSource.DataSource = ci;
}
private void btnSave_Click(object sender, EventArgs e)
{
DataContractSerializer serializer = new DataContractSerializer(typeof(CustomerInfo));
FileStream writer = new FileStream(#"C:\Users\me\temp\testme.xml", FileMode.Create);
serializer.WriteObject(writer,ci);
writer.Close();
}
// You must apply a DataContractAttribute or SerializableAttribute
// to a class to have it serialized by the DataContractSerializer.
[DataContract(Name = "Customer", Namespace = "net.ElectronicCanvas")]
public class CustomerInfo
{
[DataMember]
public string CustomerName { get; set; }
[DataMember]
public PhoneInfo PhonePrimary { get; set; }
[DataMember]
public PhoneInfo PhoneDays { get; set; }
[DataMember]
public PhoneInfo PhoneEvening { get; set; }
// Constructor is needed to instantiate the PhoneInfo classes
// within the CustomerInfo class
public CustomerInfo()
{
PhonePrimary = new PhoneInfo();
PhoneDays = new PhoneInfo();
PhoneEvening = new PhoneInfo();
}
}
public class PhoneInfo
{
public string number { get; set; }
public string type { get; set; }
public bool textOk { get; set; }
}
}
}

First of all you need to decide whether to use databinding or manipulate Text property directly. Those two approaches should not be mixed together.
If you want to use databinding than you are missing one line in the code:
public Form1()
{
InitializeComponent();
customerInfoBindingSource.DataSource = ci; // This is the missing line
}
You need to let your customerInfoBindingSource know about the data source.
If you add this line, then the Text that is assigned in design time will be overridden by the text from your bound data source. If you want to use binding you should manipulate with the data source instead of setting Text fields directly. Like this:
public Form1()
{
InitializeComponent();
ci.CustomerName = "TestCustomerName";
customerInfoBindingSource.DataSource = ci;
}