Add Demo

Src/Asp.Net/SqlServerTest/4_JoinQuery.cs

@@ -0,0 +1,171 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using static OrmTest._4_JoinQuery;
+
+namespace OrmTest
+{
+    internal class _4_JoinQuery
+    {
+        public static void Init()
+        {
+            InitializeDatabase();
+            SyntaxSugar1();
+            SyntaxSugar2();
+            SyntaxSugar3();
+        }
+        /// <summary>
+        /// 使用语法糖1进行联表查询。
+        /// Performs a Join query using Syntax Sugar 1.
+        /// </summary>
+        /// <returns>查询结果列表。The list of query results.</returns>
+        public static List<ViewOrder2> SyntaxSugar1()
+        {
+            var db = DbHelper.GetNewDb();
+            var query = db.Queryable<Order>()
+                .LeftJoin<Custom>((o, cus) => o.CustomId == cus.Id)
+                .LeftJoin<OrderDetail>((o, cus, oritem) => o.Id == oritem.OrderId)
+                .Where(o => o.Id == 1)
+                .Select((o, cus, oritem) => new ViewOrder2 { Id = o.Id,Name=o.Name, CustomName = cus.Name })
+                .ToList();
+
+            return query;
+        }
+
+        /// <summary>
+        /// 使用语法糖2进行联表查询。
+        /// Performs a Join query using Syntax Sugar 2.
+        /// </summary>
+        /// <returns>查询结果列表。The list of query results.</returns>
+        public static List<Order> SyntaxSugar2()
+        {
+            var db = DbHelper.GetNewDb();
+            var rightQueryable = db.Queryable<Custom>()
+                .LeftJoin<OrderDetail>((o, i) => o.Id == i.Id)
+                .Select(o => o);
+
+            var list = db.Queryable<Order>()
+                .LeftJoin(rightQueryable, (c, j) => c.CustomId == j.Id)
+                .Select(c => c)
+                .ToList();
+            return list;
+        }
+
+        /// <summary>
+        /// 使用语法糖3进行联表查询。
+        /// Performs a Join query using Syntax Sugar 3.
+        /// </summary>
+        /// <returns>查询结果列表。The list of query results.</returns>
+        public static List<ViewOrder2> SyntaxSugar3()
+        {
+            var db = DbHelper.GetNewDb();
+            var list = db.Queryable<Order, OrderItem, Custom>((o, i, c) => o.Id == i.OrderId && c.Id == o.CustomId)
+                .Select((o, i, c) => new ViewOrder2 { Id = o.Id, Name = o.Name, CustomName = c.Name })
+                .ToList();
+
+            return list;
+        }
+         
+
+        static void InitializeDatabase()
+        {
+            // Initialize order data
+            // 初始化订单数据
+            var orders = new List<Order>
+            {
+                new Order { Id = 1, Name = "Order 1", CustomId = 1 },
+                new Order { Id = 2, Name = "Order 2", CustomId = 2 },
+                new Order { Id = 3, Name = "Order 3", CustomId = 1 },
+            };
+
+            // Initialize order details data
+            // 初始化订单详情数据
+            var orderDetails = new List<OrderDetail>
+            {
+                new OrderDetail { Id = 1, OrderId = 1 },
+                new OrderDetail { Id = 2, OrderId = 2 },
+                new OrderDetail { Id = 3, OrderId = 3 },
+            };
+
+            // Initialize customer data
+            // 初始化客户数据
+            var customers = new List<Custom>
+            {
+                new Custom { Id = 1, Name = "Customer 1" },
+                new Custom { Id = 2, Name = "Customer 2" },
+                new Custom { Id = 3, Name = "Customer 3" },
+            };
+
+            // Get database connection
+            // 获取数据库连接
+            var db = DbHelper.GetNewDb();
+
+            // Initialize database tables and truncate data
+            // 初始化数据库表并清空数据
+            db.CodeFirst.InitTables<Custom, OrderDetail, Order>();
+            db.DbMaintenance.TruncateTable<Custom, OrderDetail, Order>();
+
+            // Insert data into tables
+            // 向表中插入数据
+            db.Insertable(orders).ExecuteCommand();
+            db.Insertable(orderDetails).ExecuteCommand();
+            db.Insertable(customers).ExecuteCommand();
+        }
+
+        /// <summary>
+        /// 订单实体类。
+        /// Order entity class.
+        /// </summary>
+        [SqlSugar.SugarTable("Order04")]
+        public class Order
+        {
+            [SqlSugar.SugarColumn(IsPrimaryKey = true, IsIdentity = true)]
+            public int Id { get; set; }
+            public string Name { get; set; }
+            public int CustomId { get; set; }
+            // 其他订单相关属性...
+        }
+
+        /// <summary>
+        /// 订单详情实体类。
+        /// Order detail entity class.
+        /// </summary>
+        [SqlSugar.SugarTable("OrderDetail04")]
+        public class OrderDetail
+        {
+            [SqlSugar.SugarColumn(IsPrimaryKey = true, IsIdentity = true)]
+            public int Id { get; set; }
+            public int OrderId { get; set; }
+            // 其他订单详情相关属性...
+        }
+
+        /// <summary>
+        /// 客户实体类。
+        /// Customer entity class.
+        /// </summary>
+        [SqlSugar.SugarTable("Custom04")]
+        public class Custom
+        {
+            [SqlSugar.SugarColumn(IsPrimaryKey = true, IsIdentity = true)]
+            public int Id { get; set; }
+            public string Name { get; set; }
+            // 其他客户相关属性...
+        }
+ 
+
+        
+        /// <summary>
+        /// 类1实体类。
+        /// Class1 entity class.
+        /// </summary>
+        public class ViewOrder2
+        {
+            public int Id { get; set; }
+            public string Name { get; set; }
+            public string CustomName { get; set; }
+            // 其他类1相关属性...
+        }
+    }
+}

Src/Asp.Net/SqlServerTest/Program.cs

@@ -11,7 +11,7 @@ namespace OrmTest
             _1_CodeFirst.Init();
             _2_DbFirst.Init();
             _3_EasyQuery.Init();
-
+            _4_JoinQuery.Init();
             Console.ReadKey();
         }
     }

Src/Asp.Net/SqlServerTest/SqlServerTest.csproj

@@ -66,6 +66,7 @@
   <ItemGroup>
     <Compile Include="1_CodeFirst.cs" />
     <Compile Include="2_DbFirst.cs" />
+    <Compile Include="4_JoinQuery.cs" />
     <Compile Include="UnitTest\Description.cs" />
     <Compile Include="3_EasyQuery.cs" />
     <Compile Include="UserTestCases\Cases\OldDemo\Demo2_Updateable.cs" />