// Entity Framework Plus

// Doc: https://entityframework-plus.net/query-filter

​

// @nuget: Microsoft.EntityFrameworkCore.SqlServer

// @nuget: Z.EntityFramework.Plus.EFCore

​

using System;

using System.Linq;

using Z.EntityFramework.Plus;

using Microsoft.EntityFrameworkCore;

using Microsoft.Data.SqlClient;

using System.Collections.Generic;

​

public class Program

{

    public static void Main()

    {

        using (var context = new EntityContext())

        {

            context.Database.EnsureCreated();

        }

        GenerateData();

​

        using (var context = new EntityContext())

        {

            int myCategoryID = 1;

​

            // CREATE filter by interface

            context.Filter<Product>(q => q.Where(x => x.CategoryId == myCategoryID));

​

            // SELECT * FROM Product WHERE CategoryID = 1

            var products = context.Products.ToList();

            FiddleHelper.WriteTable(products);

        }

    }

​

    public static void GenerateData()

    {

        using (var context = new EntityContext())

        {

            context.Categories.Add(new Category() { Name = "Category_A" });

            context.Categories.Add(new Category() { Name = "Category_B" });

​

            context.Products.Add(new Product() { Name = "Product_A", CategoryId = 1 });

            context.Products.Add(new Product() { Name = "Product_B", CategoryId = 2 });

            context.Products.Add(new Product() { Name = "Product_C", CategoryId = 1 });

​

            context.SaveChanges();

        }

    }

​

    public class EntityContext : DbContext

    {

        public EntityContext() 

        {

        }

​

        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)

        {

            optionsBuilder.UseSqlServer(new SqlConnection(FiddleHelper.GetConnectionStringSqlServer()));

​

            base.OnConfiguring(optionsBuilder);

        }

        public DbSet<Product> Products { get; set; }

        public DbSet<Category> Categories { get; set; }

    }

​

    public class Product

    {

        public int ProductId { get; set; }

        public string Name { get; set; }

        public int CategoryId { get; set; }

    }

​

    public class Category

    {

        public int CategoryId { get; set; }

        public string Name { get; set; }

    }

}