AY的Dapper研究学习-基本入门-C#开发-aaronyang技术分享

原文:AY的Dapper研究学习-基本入门-C#开发-aaronyang技术分享

====================www.ayjs.net       杨洋    wpfui.com        ayui      ay  aaronyang=======请不要转载谢谢了。=========

本文，是AY 看github源码，和网上一些博客，文章 整理，写出来的。目前还没找到系统级别的教程

先建立.net framework4.6的控制台项目,添加nuget引用

新建了 Sqlserver的数据库TestDapper

SQL

CREATE TABLE [dbo].[Users](
    [UserID] [int] IDENTITY(1,1) NOT NULL,
    [UserName] [varchar](50) NULL,
    [Email] [varchar](100) NULL,
    [Address] [varchar](100) NULL,
 CONSTRAINT [PK_Users] PRIMARY KEY CLUSTERED
(
    [UserID] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
) ON [PRIMARY]  

CREATE TABLE [dbo].[Product](
    [ProductID] [int] IDENTITY(1,1) NOT NULL,
    [ProductName] [varchar](220) NULL,
    [ProductDesc] [varchar](220) NULL,
    [UserID] [int] NULL,
    [CreateTime] [datetime] NULL,
 CONSTRAINT [PK_Product] PRIMARY KEY CLUSTERED
(
    [ProductID] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
) ON [PRIMARY]

连接：

C#

      var con = new SqlConnection(ConfigurationManager.ConnectionStrings["sql"].ConnectionString);

新增后，返回新增ID-  MsSql：

C#

 var id = con.QueryFirst<int>("insert into users values('ay', 'ay2015@qq.com', '合肥市润安大厦');select  @@IDENTITY;");

新增后，返回新增ID-  MySql：

C#

var id = con.QueryFirst<int>("insert into users values(null, 'ay', 'ay2015@qq.com', '合肥市润安大厦');select last_insert_id();");

参数赋值，Query返回一个列表，这里Users这个Model是自己声明的：

C#

var u = con.Query<Users>("select * from Users where UserID = @UserID", new { UserID = 1 });
            Console.WriteLine(u.First().UserName);

使用Execute执行 更删改sql，返回int，应该是受影响的行数

通过Execute执行update

C#

            con.Execute("update users set UserName = '李四川' where UserId = @UserId", new { UserId = 3 });
            var u = con.Query<Users>("select * from Users where UserId = @UserId", new { UserId = 3});
            Console.WriteLine(u.First().UserName);

删除

C#

  con.Execute("delete from users where UserId = @UserId", new { UserId = 3 });
            var us = con.Query<Users>("select * from Users");
            foreach (var item in us)
            {
                Console.WriteLine(item.UserName);
            }

增加数据

C#

   var id = con.QueryFirst<int>("insert into users values('ay163', 'ay163@163.com', '合肥市润安大厦11');select  @@IDENTITY;");

IN操作的处理

C#

    var uss = con.Query<Users>("select * from Users where UserId in @UserIds", new { UserIds = new List<int> {1,2 } });
            foreach (var item in uss)
            {
                Console.WriteLine(item.UserName);
            }

插入一条数据

C#

 var id = con.Execute($"insert into Product values('WCF编程宝典', 'WCF基本入门的一本书籍', 1,'{DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss")}')");

多条sql查询反馈，我感觉这个设计真的好

C#

   //多条sql执行
            var sql = "select * from Product; select * from Users";
            using (var multiReader = con.QueryMultiple(sql))
            {
                var productList = multiReader.Read<Product>();
                var userList = multiReader.Read<Users>();
                foreach (var item in productList)
                {
                    Console.WriteLine(item.ProductName);
                }

                foreach (var item in userList)
                {
                    Console.WriteLine(item.UserName);
                }
            }

关于多表查询的，假如1个表有个导航属性

Product加一个Users类型的User属性，使用 splitOn

C#

          var sql = @"select  p.ProductName,p.CreateTime,u.UserName
                        from Product as p
                        join Users as u
                        on p.UserID = u.UserID
                        where p.CreateTime > '2015-12-12'; ";

            var productList = con.Query<Product, Users, Product>(sql,
                                    (product, users) =>
                                    {
                                        product.User = users; return product;
                                    }, splitOn: "UserName");
            foreach (var item in productList)
            {
                Console.WriteLine(item.ProductName+" "+item.User.UserName);
            }

我把sql语句的createtime和u.username位置换了下

效果，日期没了，

如果位置换回来，又有了，说明是从右往左  分割复制的，只要列 不要是由2张表以上的列成员组成的就

如果你觉得很难理解，你可以新建一个类，把你的要返回的列，写成对应属性，效果一样的。

C#

  var sql = @"select  p.ProductName,p.CreateTime,u.UserName
                        from Product as p
                        join Users as u
                        on p.UserID = u.UserID
                        where p.CreateTime > '2015-12-12'; ";

            var productList = con.Query<TAY>(sql);
            foreach (var item in productList)
            {
                Console.WriteLine(item.ProductName + " " + item.CreateTime + " " + item.UserName);
            }

C#

  public class TAY
    {
        public string ProductName { get; set; }
        public DateTime CreateTime { get; set; }

        public string UserName { get; set; }
    }

执行存储过程，根据ID查询用户

SQL

USE TestDapper
GO
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
Create proc [dbo].[sp_GetUsers]
 @id int
as
begin
select * from Users where UserID = @id ;
end

代码简单，没的讲

C#

  var userList = con.Query<Users>("sp_GetUsers", new { id = 1 },
                            commandType: CommandType.StoredProcedure);

            foreach (var item in userList)
            {
                Console.WriteLine(item.UserName);
            }

批量插入怎么写？

C#

  List<Users> user = new List<Users>();
            for (int i = 1; i <= 1000; i++)
            {
                Users u = new Users();
                u.UserName = "AY " + i;
                u.Email = "EM " + i;
                u.Address = "AD " + i;
                user.Add(u);
            }
            con.Execute("insert users(UserName,Email,Address) values(@UserName,@Email,@Address)", user);
            var userList = con.Query<Users>("select * from users");
            foreach (var item in userList)
            {
                Console.WriteLine(item.UserName);
            }

我个人觉得不太喜欢，查询如下

C#

  var userList = con.Query<Users>("select * from users where UserName like  '%测试%'");
            foreach (var item in userList)
            {
                Console.WriteLine(item.UserName);
            }

C#

  System.Diagnostics.Stopwatch sw = new System.Diagnostics.Stopwatch();
            sw.Start();
            StringBuilder sb = new StringBuilder("insert users(UserName,Email,Address) ");
            for (int i = 1; i <= 1000; i++)
            {
                if (i == 1000)
                    sb.Append(string.Format("select '{0}','{1}','{2}' ", "用户" + i, "邮箱" + i, "地址" + i));
                else
                {
                    sb.Append(string.Format("select '{0}','{1}','{2}' UNION ", "用户" + i, "邮箱" + i, "地址" + i));
                }
            }
            sw.Stop();
            Console.WriteLine(sw.ElapsedMilliseconds.ToString());
            sw.Start();
            var _resultCount = con.Execute(sb.ToString());
            Console.WriteLine(_resultCount);
            sw.Stop();
            Console.WriteLine(sw.ElapsedMilliseconds.ToString());

当然肯定是不推荐以上两种，推荐SqlServer的BulkCopy

C#

    public bool SqlServerBulkInsert(DataTable table, string connectionString)
        {
            try
            {
                using (SqlConnection conn = new SqlConnection(connectionString))
                {
                    conn.Open();
                    SqlTransaction trans = conn.BeginTransaction();

                    SqlBulkCopy sqlbulkCopy = new SqlBulkCopy(conn, SqlBulkCopyOptions.Default, trans);
                    // 设置源表名称
                    sqlbulkCopy.DestinationTableName = table.TableName;
                    //分几次拷贝
                    //sqlbulkCopy.BatchSize = 10;
                    // 设置超时限制
                    sqlbulkCopy.BulkCopyTimeout = CommandTimeOut;
                    foreach (DataColumn dtColumn in table.Columns)
                    {
                        sqlbulkCopy.ColumnMappings.Add(dtColumn.ColumnName, dtColumn.ColumnName);
                    }
                    try
                    {
                        // 写入
                        sqlbulkCopy.WriteToServer(table);
                        // 提交事务
                        trans.Commit();
                        return true;
                    }
                    catch(Exception ex)
                    {
                        trans.Rollback();
                        sqlbulkCopy.Close();
                        return false;
                    }
                    finally
                    {
                        conn.Close();
                        conn.Dispose();
                        sqlbulkCopy.Close();
                    }
                }
            }
            catch (Exception e)
            {

                return false;
            }
        }

====================www.ayjs.net       杨洋    wpfui.com        ayui      ay  aaronyang=======请不要转载谢谢了。=========

我先写这么多吧，下篇博客继续

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