1. Service Root Url یا ریشه آدرس سرویس که آدرس و نام وب سرویس را مشخص می‌سازد.
2. Resource Path یا مسیر منابع که امکان دسترسی به منابع موجود وب سرویس را فراهم می‌سازد.
3. Query Options یا گزینه‌های کوئری که امکان کوئری نویسی با استفاده از عملگرها و پارامترهای گرامر OData را فراهم می‌سازد.

http://services.odata.org/OData/OData.svc/Category(1)/Products?$top=2&$orderby=name
\_______________________________________/ \__________________/ \__________________/
               |                                |                    |
         service root URL                  resource path        query options

http://services.odata.org/OData/OData.svc/Products

http://services.odata.org/OData/OData.svc/Products(1)/Supplier

http://services.odata.org/OData/OData.svc/Products/MostExpensive

http://services.odata.org/OData/OData.svc/GetProductsByCategoryId(categoryId=2)

http://services.odata.org/OData/OData.svc/Products(1)/Name

//filter
http://services.odata.org/OData/OData.svc/Products?$filter=Name eq 'Milk'
//orderby
http://services.odata.org/OData/OData.svc/Products?$orderby=Name
//skip
http://services.odata.org/OData/OData.svc/Products?$skip=5
//top
http://services.odata.org/OData/OData.svc/Products?$top=10
//expand
http://services.odata.org/OData/OData.svc/Products?$expand=Category

1. eq عملگر برابری
2. ne عملگر مخالف
3. lt عملگر کوچکتری
4. le عملگر کوچکتر یا مساوی
5. gt عملگر بزرگنری
6. ge عملگر بزرگتر یا مساوی
7. and
8. or
9. not

1. add جمع دو عملوند
2. sub تفریق دو عملوند
3. mul ضرب دو عملوند
4. div تقیسم دو عملوند
5. mod باقیمانده تقسیم دو عملوند

public class Supplier
{
    [Key]
    public string Key {get; set; }
    public string Name { get; set; }
}
public class Category
{
    public int ID { get; set; }
    public string Name { get; set; }
    public virtual ICollection<Product> Products { get; set; }
}

public class Product
{
    public int ID { get; set; }
    public string Name { get; set; }
    public decimal Price { get; set; }

    [ForeignKey("Category")]
    public int CategoryId { get; set; }
    public Category Category { get; set; }

    [ForeignKey("Supplier")]
    public string SupplierId { get; set; }
    public virtual Supplier Supplier { get; set; }
}

public static void Register(HttpConfiguration config)
        {
            ODataModelBuilder odataModelBuilder = new ODataConventionModelBuilder();

            var product = odataModelBuilder.EntitySet<Product>("Products");
            var category = odataModelBuilder.EntitySet<Category>("Categories");
            var supplier = odataModelBuilder.EntitySet<Supplier>("Suppliers");

            var edmModel = odataModelBuilder.GetEdmModel();

            supplier.EntityType.Ignore(c => c.Name);

            config.Select(System.Web.OData.Query.QueryOptionSetting.Allowed);
            config.MaxTop(25);
            config.OrderBy(System.Web.OData.Query.QueryOptionSetting.Allowed);
            config.Count(System.Web.OData.Query.QueryOptionSetting.Allowed);
            config.Expand(System.Web.OData.Query.QueryOptionSetting.Allowed);
            config.Filter(System.Web.OData.Query.QueryOptionSetting.Allowed);
            config.Count(System.Web.OData.Query.QueryOptionSetting.Allowed);

            //config.MapODataServiceRoute("ODataRoute", "odata", edmModel); // کانفیگ به صورت معمولی
           config.MapODataServiceRoute("ODataRoute", "odata",
                builder =>
                {
                    builder.AddService(ServiceLifetime.Singleton, sp => edmModel);
                    builder.AddService<IEnumerable<IODataRoutingConvention>>(ServiceLifetime.Singleton, sp => ODataRoutingConventions.CreateDefault());
                });
}

[EnableQuery]
        public IQueryable<Product> Get()
        {
            return new List<Product>
            {
                new Product { Id = 1, Name = "name 1", Price = 11, Category = new Category {Id =1, Name = "Cat1" } },
                new Product { Id = 2, Name = "name 2", Price = 12, Category = new Category {Id =2, Name = "Cat2" } },
                new Product { Id = 3, Name = "name 3", Price = 13, Category = new Category {Id =3, Name = "Cat3" } },
                new Product { Id = 4, Name = "name 4", Price = 14, Category = new Category {Id =4, Name = "Cat4" } },
            }.AsQueryable(); ;
        }

/odata/Products?$select=Id,Name

/odata/Products?$top=3&$skip=2

/odata/Products?$count=true

{@odata.context: "http://localhost:4516/odata/$metadata#Products", @odata.count: 4,…}
@odata.context:"http://localhost:4516/odata/$metadata#Products"
@odata.count:4
value:[{Id: 1, Name: "name 1", Price: 11, SupplierId: 0, CategoryId: 0},…]
0:{Id: 1, Name: "name 1", Price: 11, SupplierId: 0, CategoryId: 0}
1:{Id: 2, Name: "name 2", Price: 12, SupplierId: 0, CategoryId: 0}
2:{Id: 3, Name: "name 3", Price: 13, SupplierId: 0, CategoryId: 0}
3:{Id: 4, Name: "name 4", Price: 14, SupplierId: 0, CategoryId: 0}

/odata/Products?$filter=Id eq 1

/odata/Products?$filter=Id gt 1 and Id lt 3

/odata/Products?$orderby=Id desc

[EnableQuery(PageSize = 10)]

[EnableQuery(AllowedLogicalOperators=AllowedLogicalOperators.Equal)]

var product = odataModelBuilder.EntitySet<Product>("Products");
product.EntityType.Ignore(e => e.Price);

[EnableQuery(AllowedOrderByProperties = "Id,Name")]

public System.Web.Http.IHttpActionResult GetName(int key)
        {
            Product product = Get().Single(c => c.Id == key);            
            return Ok(product.Name);
        }

HTTP/1.1 200 OK
Content-Type: text/plain; charset=utf-8
DataServiceVersion: 3.0
Content-Length: 3

Ali

public class Product
    {
        public int Id { get; set; }
        public string Name { get; set; }

        [NotFilterable, NotSortable]
        public decimal Price { get; set; }

        [ForeignKey(nameof(SupplierId))]
        [NotNavigable]
        public virtual Supplier Supplier { get; set; }
        public int SupplierId { get; set; }


        [ForeignKey(nameof(CategoryId))]
        public virtual Category Category { get; set; }
        public int CategoryId { get; set; }

        [NotExpandable]
        public virtual ICollection<TestEntity> TestEnities { get; set; }
    }

public DateTimeOffset CreatedOn { get; set; }

/odata/Products?$filter=year(CreatedOn) eq 2016

/odata/Products?$filter=CreatedOn lt cast(2017-04-01T04:11:31%2B08:00,Edm.DateTimeOffset)

/odata/Categories?$expand=Products($filter=Id gt 1 and Id lt 5)

/odata/Categories?$expand=Products($select=Id,Name)

public class MyEnableQueryAttribute : EnableQueryAttribute
{
    public override IQueryable ApplyQuery(IQueryable queryable, ODataQueryOptions queryOptions)
    {
       // Don't apply Skip and Top.
       var ignoreQueryOptions = AllowedQueryOptions.Skip | AllowedQueryOptions.Top;
       return queryOptions.ApplyTo(queryable, ignoreQueryOptions);
    }
}

 public class CaseInsensitiveResolver : ODataUriResolver
    {
        private bool _enableCaseInsensitive;

        public override bool EnableCaseInsensitive
        {
            get { return true; }
            set { _enableCaseInsensitive = value; }
        }
    }

config.MapODataServiceRoute("ODataRoute", "odata",
                builder =>
                {
                    builder.AddService(ServiceLifetime.Singleton, sp => edmModel);
                    builder.AddService<IEnumerable<IODataRoutingConvention>>(ServiceLifetime.Singleton, sp => ODataRoutingConventions.CreateDefault());
                    builder.AddService<ODataUriResolver>(ServiceLifetime.Singleton, sp => new CaseInsensitiveResolver()); // how enable case sensitive
                });

Install-Package Microsoft.AspNet.Odata

namespace ProductService.Models
{
    public class Product
    {
        public int Id { get; set; }
        public string Name { get; set; }
        public decimal Price { get; set; }
        public string Category { get; set; }
    }
}

Install-Package EntityFramework

<connectionStrings>
    <add name="ProductsContext" connectionString="Data Source=.; 
        Initial Catalog=ProductsContext; Integrated Security=True;MultipleActiveResultSets=True;"
      providerName="System.Data.SqlClient" />
  </connectionStrings>

using System.Data.Entity;
namespace ProductService.Models
{
    public class ProductsContext : DbContext
    {
        public ProductsContext() 
                : base("name=ProductsContext")
        {
        }
        public DbSet<Product> Products { get; set; }
    }
}

public static class WebApiConfig
{
    public static void Register(HttpConfiguration config)
    {
        ODataModelBuilder builder = new ODataConventionModelBuilder();
        builder.EntitySet<Product>("Products");
        config.MapODataServiceRoute(
            routeName: "ODataRoute",
            routePrefix: null,
            model: builder.GetEdmModel());
    }
}

using ProductService.Models;
using System.Data.Entity;
using System.Data.Entity.Infrastructure;
using System.Linq;
using System.Net;
using System.Threading.Tasks;
using System.Web.Http;
using System.Web.OData;
namespace ProductService.Controllers
{
    public class ProductsController : ODataController
    {
        ProductsContext db = new ProductsContext();
        private bool ProductExists(int key)
        {
            return db.Products.Any(p => p.Id == key);
        } 
        protected override void Dispose(bool disposing)
        {
            db.Dispose();
            base.Dispose(disposing);
        }
    }
}

[EnableQuery]
public IQueryable<Product> Get()
{
    return db.Products;
}
[EnableQuery]
public SingleResult<Product> Get([FromODataUri] int key)
{
    IQueryable<Product> result = db.Products.Where(p => p.Id == key);
    return SingleResult.Create(result);
}

public async Task<IHttpActionResult> Post(Product product)
{
    if (!ModelState.IsValid)
    {
        return BadRequest(ModelState);
    }
    db.Products.Add(product);
    await db.SaveChangesAsync();
    return Created(product);
}

public async Task<IHttpActionResult> Patch([FromODataUri] int key, Delta<Product> product)
{
    if (!ModelState.IsValid)
    {
        return BadRequest(ModelState);
    }
    var entity = await db.Products.FindAsync(key);
    if (entity == null)
    {
        return NotFound();
    }
    product.Patch(entity);
    try
    {
        await db.SaveChangesAsync();
    }
    catch (DbUpdateConcurrencyException)
    {
        if (!ProductExists(key))
        {
            return NotFound();
        }
        else
        {
            throw;
        }
    }
    return Updated(entity);
}
public async Task<IHttpActionResult> Put([FromODataUri] int key, Product update)
{
    if (!ModelState.IsValid)
    {
        return BadRequest(ModelState);
    }
    if (key != update.Id)
    {
        return BadRequest();
    }
    db.Entry(update).State = EntityState.Modified;
    try
    {
        await db.SaveChangesAsync();
    }
    catch (DbUpdateConcurrencyException)
    {
        if (!ProductExists(key))
        {
            return NotFound();
        }
        else
        {
            throw;
        }
    }
    return Updated(update);
}

public async Task<IHttpActionResult> Delete([FromODataUri] int key)
{
    var product = await db.Products.FindAsync(key);
    if (product == null)
    {
        return NotFound();
    }
    db.Products.Remove(product);
    await db.SaveChangesAsync();
    return StatusCode(HttpStatusCode.NoContent);
}

http://localhost:YourPort/Products

{
  "@odata.context":"http://localhost:4516/$metadata#Products","value":[
    {
      "Id":1,"Name":"Ali","Price":2.00,"Category":"aaa"
    },{
      "Id":2,"Name":"Reza","Price":1.00,"Category":"bbb"
    },{
      "Id":3,"Name":"Ahmad","Price":0.00,"Category":"ccc"
    }
  ]
}

/Products(2)

/Products?$filter=Id gt 1

Products?$select=Name

Products?$select=Name,Price

/Products?$top=3

1. یک ASP.NET Web Application با نام NorthwindService ایجاد نمایید و بر روی پروژه راست کلیک کنید و از منوی Add گزینه New Item را انتخاب نمایید  از پنجره باز شده از دسته Data گزینه ADO.NET Entity Data Model  را انتخاب و نام ان را Northwind بگذارید.
   
2. از پنجره باز شده Generate from Databaseرا انتخاب و با انتخاب کانکشن از نوع Sql Server Compact 4  اتصال به فایل Northwind.sdf را انتخاب تا کلاس‌های لازم تولید شود.
   
3. برای تولید data service بر روی پروژه راست کلیک کنید و از منوی Add گزینه New Item را انتخاب نمایید از پنجره باز شده گزینه  WCF Data Service را انتخاب و نام آن را Northwind.svc بگذارید. کد زیر خودکار تولید می‌شود
   

    public class Northwind : DataService< /* TODO: put your data source class name here */ >
       {
           // This method is called only once to initialize service-wide policies.
           public static void InitializeService(DataServiceConfiguration config)
           {
               // TODO: set rules to indicate which entity sets and service operations are visible, updatable, etc.
               // Examples:
               // config.SetEntitySetAccessRule("MyEntityset", EntitySetRights.AllRead);
               // config.SetServiceOperationAccessRule("MyServiceOperation", ServiceOperationRights.All);
               config.DataServiceBehavior.MaxProtocolVersion = DataServiceProtocolVersion.V3;
           }
       }

4. برای دسترسی به موجودیت‌های Northwind بجای عبارت put your data source نام مدل را تایپ کنید
   

   public class Northwind : DataService<NorthwindEntities>

5. برای فعال کردن دسترسی به منابع data source متغیر config کلاس DataServiceConfiguration را بصورت زیر تنظیم نمایید. تابع SetEntitySetAccessRule با گرفتن نام موجودیت و نحوه دسترسی امکان استفاده از این موجودیت را با استفاده از WCF Data Service فزاهم می‌نمایید. مثلا در زیر امکان دسترسی به موجودیت Orders را با امکان خواندن همه، نوشتن ادقامی و جایگزین فراهم نموده است.
   

   config.SetEntitySetAccessRule("Orders", EntitySetRights.AllRead 
        | EntitySetRights.WriteMerge 
        | EntitySetRights.WriteReplace );
   config.SetEntitySetAccessRule("Customers", EntitySetRights.AllRead);

6. اگر بخواهیم امکان خواندن همه موجودیت‌ها را فراهم کنیم از کد زیر می‌توانیم استفاده نمایید که * به معنای همه موجودیت‌های data model می‌باشد
   

   config.SetEntitySetAccessRule("*", EntitySetRights.AllRead);

1. بر روی Solution پروژه جاری راست کلیک و از منوی Add گزینه New Project را انتخاب و یک پروژه از نوع WPF Application با نام NorthwindClient ایجاد نمایید.
2. در پنجره MainWindow مانند کد زیر از یک Combobox و DataGrid برای نمایش اطلاعات استفاده نمایید
   

       <Window x:Class="MainWindow"
       xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
       xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
       Title="Northwind Orders" Height="335" Width="425" 
           Name="OrdersWindow" Loaded="Window1_Loaded">
       <Grid Name="orderItemsGrid">
           <ComboBox DisplayMemberPath="Order_ID" ItemsSource="{Binding}"
                     IsSynchronizedWithCurrentItem="true" 
                     Height="23" Margin="92,12,198,0" Name="comboBoxOrder" VerticalAlignment="Top"/>
           <DataGrid ItemsSource="{Binding Path=Order_Details}"  
                     CanUserAddRows="False" CanUserDeleteRows="False"  
                     Name="orderItemsDataGrid" Margin="34,46,34,50"
                     AutoGenerateColumns="False">
               <DataGrid.Columns>
                   <DataGridTextColumn  Header="Product" Binding="{Binding Product_ID, Mode=OneWay}" />
                   <DataGridTextColumn  Header="Quantity" Binding="{Binding Quantity, Mode=TwoWay}" />
                   <DataGridTextColumn  Header="Price" Binding="{Binding UnitPrice, Mode=TwoWay}" />
                   <DataGridTextColumn  Header="Discount" Binding="{Binding Discount, Mode=TwoWay}" />                
               </DataGrid.Columns>     
           </DataGrid>
           <Label Height="28" Margin="34,12,0,0" Name="orderLabel" VerticalAlignment="Top" 
                  HorizontalAlignment="Left" Width="65">Order:</Label>
           <StackPanel Name="Buttons" Orientation="Horizontal" HorizontalAlignment="Right" 
                       Height="40" Margin="0,257,22,0">
               <Button Height="23" HorizontalAlignment="Right" Margin="0,0,12,12" 
                   Name="buttonSave" VerticalAlignment="Bottom" Width="75" 
                       Click="buttonSaveChanges_Click">Save Changes
               </Button>
               <Button Height="23" Margin="0,0,12,12" 
                   Name="buttonClose" VerticalAlignment="Bottom" Width="75" 
                       Click="buttonClose_Click">Close</Button>
           </StackPanel>
       </Grid>
   </Window>

   
   
3. برای ارجاع به wcf data service بر روی پروژه راست کلیک و گزینه Add Service Reference را انتخاب نمایید در پنجره باز شده گزینه Discover را انتخاب تا سرویس را یافته و نام Namespase را Northwind بگذارید.
4. حال مانند کد زیر یک شی از مدل NorthwindEntities با آدرس وب سرویس ایجاد نموده ایم و نتیحه کوئری با استفاده از کلاس DataServiceCollection به DataContext گرید انتصاب داده ایم که البته پیش فرض آن آشنایی با DataBinding در WPF است.
   

           private NorthwindEntities context;
           private string customerId = "ALFKI";
           private Uri svcUri = new Uri("http://localhost:8358/Northwind.svc");
   
           private void Window1_Loaded(object sender, RoutedEventArgs e)
           {
               try
               {
                   context = new NorthwindEntities(svcUri);
                   var ordersQuery = from o in context.Orders.Expand("Order_Details")
                                     where o.Customers.Customer_ID == customerId
                                     select o;
                   DataServiceCollection<Orders> customerOrders = new DataServiceCollection<Orders>(ordersQuery);
                   this.orderItemsGrid.DataContext = customerOrders;
               }
               catch (Exception ex)
               {
                   MessageBox.Show(ex.ToString());
               }
           }
   

5. با صدا زدن تابع SaveChanges مدل می‌توانید تغییرات را در پایگاه داده ذخیره نمایید.
   

   private void buttonSaveChanges_Click(object sender, RoutedEventArgs e)
   {
       try
       {
           context.SaveChanges();
       }
       catch (DataServiceRequestException ex)
       {
           MessageBox.Show(ex.ToString());
   
       }
   }

   
   

1. برنامه را اجرا نمایید تا خروجی کار را مشاهده نمایید. مقادیر Quantity را تغییر دهید و دکمه Save Changes را انتخاب تا تغییرات دخیره شود.

namespace ProductService.Models
{
    public class ProductRating
    {
        public int ID { get; set; }
        public int Rating { get; set; }
        public int ProductID { get; set; }
        public virtual Product Product { get; set; }  
    }
}

ODataModelBuilder builder = new ODataConventionModelBuilder();
builder.EntitySet<Product>("Products");

builder.Namespace = "ProductService";
builder.EntityType<Product>()
    .Action("Rate")
    .Parameter<int>("Rating");

[HttpPost]
public async Task<IHttpActionResult> Rate([FromODataUri] int key, ODataActionParameters parameters)
{
    if (!ModelState.IsValid)
    {
        return BadRequest();
    }

    int rating = (int)parameters["Rating"];
    db.Ratings.Add(new ProductRating
    {
        ProductID = key,
        Rating = rating
    });

    await db.SaveChangesAsync();
    
    return StatusCode(HttpStatusCode.NoContent);
}

POST http://localhost/Products(1)/ProductService.Rate HTTP/1.1
Content-Type: application/json
Content-Length: 12

{"Rating":5}

HttpClient client = new HttpClient();
var response = client.PostAsync(postUrl, new StringContent(JsonConvert.SerializeObject(new { Rating = 5 }), Encoding.UTF8, "application/json")).Result;

ODataModelBuilder builder = new ODataConventionModelBuilder();
builder.EntitySet<Product>("Products");
builder.EntitySet<Supplier>("Suppliers");

builder.Namespace = "ProductService";
builder.EntityType<Product>().Collection
    .Function("MostExpensive")
    .Returns<double>();

ReturnsFromEntitySet<Product>("Products")

ReturnsCollectionFromEntitySet<Product>("Products");

ReturnsCollection<string>();

GET http://localhost/Products/ProductService.MostExpensive

public class ProductsController : ODataController
{
    [HttpGet]
    public IHttpActionResult MostExpensive()
    {
        var product = db.Products.Max(x => x.Price);
        return Ok(product);
    }

    // Other controller methods not shown.
}

HTTP/1.1 200 OK
Content-Type: application/json; odata.metadata=minimal; odata.streaming=true
OData-Version: 4.0
Date: Sat, 28 Jun 2016 00:44:07 GMT
Content-Length: 85

{
  "@odata.context":"http://localhost:38479/$metadata#Edm.Decimal","value":50.00
}

ODataModelBuilder builder = new ODataConventionModelBuilder();
builder.EntitySet<Product>("Products");

builder.Function("GetSalesTaxRate")
    .Returns<double>()
    .Parameter<int>("PostalCode");

[HttpGet]
[ODataRoute("GetSalesTaxRate(PostalCode={postalCode})")]
public IHttpActionResult GetSalesTaxRate([FromODataUri] int postalCode)
{
    double rate = 5.6;  // Use a fake number for the sample.
    return Ok(rate);
}

GET http://localhost/GetSalesTaxRate(PostalCode=10) HTTP/1.1

HTTP/1.1 200 OK
Content-Type: application/json; odata.metadata=minimal; odata.streaming=true
OData-Version: 4.0
Date: Sat, 28 Jun 2016 01:05:32 GMT
Content-Length: 82

{
  "@odata.context":"http://localhost:38479/$metadata#Edm.Double","value":5.6
}

dotnet new webapi -o SampleApi

<PackageReference Include="Microsoft.AspNetCore.Mvc.NewtonsoftJson" Version="3.1.3" />
<PackageReference Include="Microsoft.AspNetCore.OData" Version="7.4.0" />

using Microsoft.AspNet.OData.Extensions;

services.AddControllers().AddNewtonsoftJson(); // Add .AddNewtonsoftJson() to services.AddControllers();
services.AddOData(); // add this new line

app.UseEndpoints(endpoints => // Existing code
{   
    endpoints.MapControllers(); // Existing code
    endpoints.EnableDependencyInjection(); // Add this new line
    endpoints.Select().Expand().Filter().OrderBy().Count().MaxTop(20); // Add this new line
});

// replace:
[HttpGet] // Existing code  
// with:
[HttpGet, EnableQuery] // new code

public class Customer
{
    public int Id { get; set; }

    public string FirstName { get; set; }

    public string LastName { get; set; }

    public Gender Gender { get; set; }

    public AddressInfo Address { get; set; }
}

public class AddressInfo
{
    public int StreetNo { get; set; }

    public string PostalCode { get; set; }
}

public enum Gender
{
    Man, Woman, Other
}  

?$filter=Gender eq 'Woman'