c# .net orm 框架 dapper.net 的应用

之前用过 entity framework 5.0 、sqlhelper 、mybatis.NET 等 orm，当然 sqlhelper 不算。

感觉都是学习陈本挺高的，配置也比较复杂，尤其是 mybatis 全是 xml ，懵逼了 ~~~~~

ef 用着不错也挺灵活，就是有些数据库不支持 如MySQL，网上也找过ef 接入 mysql 的方法，觉得还是比较繁重

mybatis 支持大多数的数据库，实体映射也相对方便，就是灵活性太差，加一个表需要配置 好几个 xml

继续寻找及灵活又有实体映射的 orm，最后选择了 dapper.Net。用过之后你也会喜欢上它的，有以下几个特性

1.类似 ado.net 的写法，灵活拼接sql

2.有实体和数据集的映射（支持一对一、一对多实体映射）

3.学习成本超级低只有两个方法 query（）、execute（）

4.可以说是 0 配置，只要在 config 中配置连接字符串就 ok了

5.类库非常小 只有一个 sqlMapper.cs 的文件（还是喜欢vs2015以前的代码，所以我用的是 dapper.net 1.4.2，上传到我的资源中）

上代码，里面包含增、删、改、查，和事务的使用（这里测试用的是mysql数据库）

一、数据脚本

 #订单表
 CREATE TABLE `order_info` (
   `order_id` int(11) NOT NULL AUTO_INCREMENT COMMENT '订单id',
   `user_id` int(11) DEFAULT NULL COMMENT '用户id',
   `order_code` char(50) DEFAULT NULL COMMENT '订单号',
   `amount` decimal(10,0) DEFAULT NULL COMMENT '订单金额',
   `create_time` timestamp(6) NULL DEFAULT NULL COMMENT '下单时间',
   `goods_count` int(11) DEFAULT NULL COMMENT '商品数量',
   PRIMARY KEY (`order_id`)
 ) ENGINE=InnoDB AUTO_INCREMENT=6 DEFAULT CHARSET=utf8

 #订单商品表
 CREATE TABLE `order_item` (
   `item_id` int(11) NOT NULL AUTO_INCREMENT COMMENT '订单内容id',
   `order_id` int(11) NOT NULL COMMENT '商品id',
   `goods_name` char(150) DEFAULT NULL COMMENT '商品名',
   `unit_price` decimal(11,0) DEFAULT NULL COMMENT '单价',
   `goods_count` int(11) DEFAULT NULL COMMENT '商品数量',
   `amount` decimal(11,0) DEFAULT NULL COMMENT '总金额',
   `create_time` timestamp(6) NULL DEFAULT NULL COMMENT '创建时间',
   `update_time` timestamp(6) NULL DEFAULT NULL COMMENT '修改时间',
   PRIMARY KEY (`item_id`)
 ) ENGINE=InnoDB AUTO_INCREMENT=8 DEFAULT CHARSET=utf8

 #用户表
 CREATE TABLE `user_info` (
   `user_id` int(11) NOT NULL AUTO_INCREMENT COMMENT '用户id',
   `user_name` char(50) DEFAULT NULL COMMENT '用户名',
   `upwd` char(50) DEFAULT NULL COMMENT '密码',
   `create_time` timestamp(6) NULL DEFAULT NULL COMMENT '创建时间',
   `update_time` timestamp(6) NULL DEFAULT NULL COMMENT '修改时间',
   `age` int(3) DEFAULT NULL COMMENT '年龄',
   `sex` char(2) DEFAULT NULL COMMENT '性别',
   PRIMARY KEY (`user_id`)
 ) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8

测试用的存储过程

 #带有输入输出参数的过程
 DELIMITER $$
 CREATE PROCEDURE `p_getUserCount`(
  _sex CHAR,
  OUT _total INT)
 BEGIN
     SET @sex = _sex;
     SELECT COUNT(*) INTO _total FROM user_info WHERE sex=@sex;
 END$$

 #返回数据集的过程
 DELIMITER ;
 CREATE DEFINER=`root`@`localhost` PROCEDURE `p_getUserInfo`(
         _userid INT
     )
 BEGIN
         SET @uid = _userid;
         SET @sql = CONCAT('select * from user_info where user_id=',@uid );
         IF(@uid<=0) THEN
             SET  @sql = 'select * from user_info';
         END IF;
         PREPARE strsql FROM @sql;#定义预处理语句
         EXECUTE strsql;
         DEALLOCATE PREPARE strsql;  #删除定义
     END$$
 DELIMITER ;

二、实体&工具类

 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;

 namespace TestDapperDotNet.Models
 {
     public class order_infoModel
     {
         public order_infoModel()
         {
             goodsList = new List();
         }

         public int order_id { set; get; }
         public int user_id { set; get; }
         public string order_code { set; get; }
         public decimal amount { set; get; }
         public DateTime create_time { set; get; }
         public int goods_count { set; get; }
         ///
         /// 下单用户信息(测试一对一映射)
         ///
         public user_infoModel userInfo { set; get; }
         ///
         /// 订单商品信息(测试一对多映射)
         ///
         public List  goodsList { set; get; }
     }

     public class order_itemModel
     {
         public int item_id { set; get; }
         public int order_id { set; get; }
         public string goods_name { set; get; }
         public decimal unit_price { set; get; }
         public int goods_count { set; get; }
         public decimal amount { set; get; }
         public DateTime create_time { set; get; }
         public DateTime update_time { set; get; }
     }

     public class user_infoModel
     {
         public int user_id { set; get; }
         public string user_name { set; get; }
         public string upwd { set; get; }
         public DateTime create_time { set; get; }
         public DateTime update_time { set; get; }
         public int age { set; get; }
         public string sex { set; get; }
     }
 }

 using System;
 using System.Collections.Generic;
 using System.Configuration;
 using System.Linq;
 using System.Text;

 namespace TestDapperDotNet
 {
     public class DbConfig
     {
         public static readonly string Test_W =
             ConfigurationManager.ConnectionStrings["test_w"].ConnectionString;
         public static readonly string Test_R =
             ConfigurationManager.ConnectionStrings["test_r"].ConnectionString;
     }
 }

三、dapper.net 测试类

 using System;
 using System.Collections.Generic;
 using System.Data;
 using System.Linq;
 using Dapper;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 using TestDapperDotNet.Models;

 namespace TestDapperDotNet
 {
     [TestClass]
     public class TestDapper
     {
         ///
         /// 获取连接字符串
         ///
         ///
         public IDbConnection GetSqlConnection()
         {
             return new MySql.Data.MySqlClient.MySqlConnection(DbConfig.Test_W); ;
         }
         ///
         /// 查询记录返回实体
         ///
         [TestMethod]
         public void TestQueryT()
         {
             using (var conn = GetSqlConnection())
             {
                 //订单表映射单条记录
                 var sql = @"SELECT * FROM order_info WHERE order_id=@order_id;";
                 var list = conn.Query(sql, new
                 {
                     order_id = 2
                 }).ToList();
                 var itme = list.FirstOrDefault();
                 Assert.IsTrue(itme.order_id == 2);

                 //订单表映射多条记录
                 sql = @"SELECT * FROM order_info";
                 list = conn.Query(sql, new
                 {
                     order_id = 2
                 }).ToList();
                 Assert.IsTrue(list != null && list.Count>0);

             }
         }

         ///
         /// 一对一映射
         /// 订单实体下有个用户信息属性，通过user_id关联
         ///
         [TestMethod]
         public void TestOneToOne()
         {
             using (IDbConnection conn = GetSqlConnection())
             {
                 var sql = @"
 SELECT a.*,b.*
 FROM
  order_info a
  JOIN user_info b
  ON a.`user_id`=b.user_id;";
                 var list = conn.Query(
                     sql
                     , (order, user) =>
                     {
                         order.userInfo = user;
                         return order;
                     }
                     , null
                     , null
                     , true
                     , "order_id"
                     , null
                     , null).ToList();

                 list.ForEach(x =>
                 {
                     Assert.IsTrue(x.userInfo.user_id == x.user_id);
                 });
                 Assert.IsTrue(true);
             }
         }

         ///
         /// 一对多映射
         ///
         [TestMethod]
         public void TestOneToMore()
         {
             using (IDbConnection conn = GetSqlConnection())
             {
                 var sql = @"
 SELECT a.*,b.*
 FROM
  order_info a
  JOIN order_item b
  ON a.order_id=b.order_id;";
                 //合并后的订单数据
                 var orderDic = new Dictionary<int, order_infoModel>();
                 var originList = conn.Query(
                     sql
                     , (order, goods) =>
                     {
                         //需要手动维护，一对多对象关系
                         order_infoModel ord;
                         if (!orderDic.TryGetValue(order.order_id, out ord))
                         {
                             ord = order;
                             orderDic.Add(order.order_id, order);
                         }
                         ord.goodsList.Add(goods);
                         return order;
                     }
                     , null
                     , null
                     , true
                     , "order_id"
                     , null
                     , null).ToList();
                 //投影一个list
                 var list = orderDic.Select(x => x.Value).ToList();

                 list.ForEach(x =>
                 {
                     x.goodsList.ForEach(o =>
                     {
                         Assert.IsTrue(o.order_id == x.order_id);
                     });
                 });
                 Assert.IsTrue(true);
             }
         }
         [TestMethod]
         public void TestInsertOne()
         {
             var user = new user_infoModel()
             {
                 user_name="tester",
                 upwd="123",
                 create_time=DateTime.Now,
                 update_time=DateTime.Now,
                 age=99,
                 sex="女"
             };
             var sql = @"
 INSERT INTO `test`.`user_info` (
   `user_id`,
   `user_name`,
   `upwd`,
   `create_time`,
   `update_time`,
   `age`,
   `sex`
 )
 VALUES
   (
     @user_id,
     @user_name,
     @upwd,
     @create_time,
     @update_time,
     @age,
     @sex
   ) ;";
             using (IDbConnection conn = GetSqlConnection())
             {
                 var n = conn.Execute(sql, user);
                 Assert.IsTrue(n == 1);
             }
         }

         ///
         /// 执行"返回数据集"的存储过程
         ///
         [TestMethod]
         public void TestCallp_getuserinfo()
         {
             #region mysql 存储过程脚本
             /*
 DELIMITER $$
 CREATE
     PROCEDURE `test`.`p_getUserInfo`(
         _userid INT
     )
     BEGIN
         SET @uid = _userid;
         SET @sql = CONCAT('select * from user_info where user_id=',@uid );
         IF(@uid<=0) THEN
             SET  @sql = 'select * from user_info';
         END IF;
         PREPARE strsql FROM @sql;#定义预处理语句
         EXECUTE strsql;
         DEALLOCATE PREPARE strsql;  #删除定义
     END$$
 DELIMITER ;
              */
             #endregion
             var sql = "p_getuserinfo";
             using (IDbConnection conn = GetSqlConnection())
             {
                 var list = conn.Query(sql,
                      new
                      {
                          _userid = 0 //查询多个
                      },
                     null,
                     true,
                     null,
                     CommandType.StoredProcedure).ToList();
                 Assert.IsTrue(list!=null);
             }
         }

         ///
         /// 执行“带有输入输出参数”的存储过程
         ///
         [TestMethod]
         public void TestCallp_getUserCount()
         {
             #region mysql 存储过程脚本
             /*
 DELIMITER $$

 CREATE PROCEDURE `p_getUserCount`(
  _sex CHAR,
  OUT _total INT)
 BEGIN
     SET @sex = _sex;
     SELECT COUNT(*) INTO _total FROM user_info WHERE sex=@sex;
 END$$

 DELIMITER ;
              */
             #endregion
             var sql = "p_getUserCount";
             DynamicParameters pars = new DynamicParameters();
             pars.Add("_sex", "女");
             pars.Add("_total", "", DbType.Int32, ParameterDirection.Output);
             using (IDbConnection conn = GetSqlConnection())
             {
                 var n = conn.Execute(sql,
                     pars,
                     null,
                     null,
                     CommandType.StoredProcedure);
                 var total = pars.Get("_total");
                 Assert.IsTrue(total > 0);
             }
         }
         [TestMethod]
         public void TestTransaction()
         {
             using (IDbConnection conn = GetSqlConnection())
             {
                 conn.Open();
                 //开始事务
                 var transaction = conn.BeginTransaction();
                 try
                 {
                     var order = new order_infoModel()
                     {
                         amount = 100,
                         create_time = DateTime.Now,
                         goods_count = 3,
                         order_code = "20160608001",
                         user_id = 2,
                     };
                     var item = new order_itemModel()
                     {
                         amount = 100,
                         create_time = DateTime.Now,
                         goods_count = 3,
                         goods_name = "001",
                         order_id = 2,
                         unit_price = 99.99M,
                         update_time = DateTime.Now
                     };
                     var sql = @"
 INSERT INTO `order_info` (
   `user_id`,
   `order_code`,
   `amount`,
   `create_time`,
   `goods_count`
 )
 VALUES
   (
     @user_id,
     @order_code,
     @amount,
     @create_time,
     @goods_count
   ) ;";
                     int n = conn.Execute(sql, order, transaction);
                     Assert.IsTrue(n == 1);
                     if (n != 1)
                     {
                         transaction.Rollback();
                         return;
                     }
                     sql = @"
 INSERT INTO `order_item` (
   `order_id`,
   `goods_name`,
   `unit_price`,
   `goods_count`,
   `amount`,
   `create_time`,
   `update_time`
 )
 VALUES
   (
     @order_id,
     @goods_name,
     @unit_price,
     @goods_count,
     @amount,
     @create_time,
     @update_time
   ) ;";
                     n = conn.Execute(sql, item, transaction);
                     Assert.IsTrue(n == 1);
                     if (n != 1)
                     {
                         transaction.Rollback();
                         return;
                     }
                     //提交事务
                     transaction.Commit();
                 }
                 catch (Exception ex)
                 {
                     //出现异常，事务Rollback
                     transaction.Rollback();
                 }
             }
         }
     }
 }