前几天偶然看到了dapper,由于以前没有用过,只用过ef core,稍微看了一下,然后写了一些简单的可复用的封装。

Dapper的用法比较接近ADO.NET所以性能也是比较快。所以我们先来看看使用ADO.NET的时候我们怎么实现代码复用的封装。

一、ADO.NET的封装案例

利用反射对ADO.NET进行封装,看代码:

DBHelper.cs:这边用的是mysql,如果要用sqlserver将MySqlConnection换成SqlConnection即可。

这个写的比较简单,如果有复杂的sql可能就支持不了了。读取配置文件的代码需要用到两个包:

using System;
using System.Collections.Generic;
using System.Data;
using System.Linq;
using System.Reflection;
using System.Text;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Configuration.Json;
using MySqlConnector;
namespace DB.Model

{

public class DBHelper

{

private static IConfiguration Configuration { get; set; }

private static readonly string ConnStr = null;

private static MySqlConnection conn;

static DBHelper()

{

//ReloadOnChange = true 当appsettings.json被修改时重新加载

Configuration = new ConfigurationBuilder()

.Add(new JsonConfigurationSource { Path = "appsettings.json", ReloadOnChange = true }).Build();

ConnStr = Configuration.GetConnectionString("MySql");

}

public static void Init()

{

if (connnull)

{

conn = new MySqlConnection(ConnStr);

conn.Open();

}

else if (conn.State ConnectionState.Closed)

{

conn.Open();

}

else if(conn.State==ConnectionState.Broken)

{

conn.Close();

conn.Open();

}

}

/// <summary>

/// 查全部

/// </summary>

/// <typeparam name="T"></typeparam>

/// <returns></returns>

public static List<T> GetDataAll<T>()

{

Init();

Type type = typeof(T);

//用type.Name代替表名

string sql = $"select * from {type.Name}";

MySqlCommand cmd = new MySqlCommand(sql, conn);

List<T> Data = new List<T>();

MySqlDataReader reader= cmd.ExecuteReader();

while (reader.Read())

{

object obj = Activator.CreateInstance(type);

foreach (PropertyInfo property in type.GetProperties())

{

property.SetValue(obj,reader[property.Name]);

}

Data.Add((T)obj);

}

reader.Close();

conn.Close();

return Data;

}

/// <summary>

/// 按id查询

/// </summary>

/// <typeparam name="T"></typeparam>

/// <param name="id"></param>

/// <returns></returns>

public static T GetDataById<T>(int id)

{

Init();

Type type = typeof(T);

string sql = $"select * from {type.Name} where id={id}";

MySqlCommand cmd = new MySqlCommand(sql, conn);

MySqlDataReader reader = cmd.ExecuteReader();

object obj = Activator.CreateInstance(type);

while (reader.Read())

{

foreach (PropertyInfo property in type.GetProperties())

{

property.SetValue(obj,reader[property.Name]);

}

}

reader.Close();

conn.Close();

return (T) obj;

}

/// <summary>

/// 单条添加数据

/// </summary>

/// <typeparam name="T"></typeparam>

/// <param name="t"></param>

/// <returns></returns>

public static int Add<T>(T t)

{

Init();

Type type = t.GetType();

Func<PropertyInfo, object> f = (x) =>

{

if (x.GetValue(t).GetType().Equals(typeof(string)))

{

return $"'{x.GetValue(t)}'";

}

else

{

return x.GetValue(t);

}

};

string sql = $"insert into {type.Name} " +

$"({string.Join(",", type.GetProperties().Select(n => $"{n.Name}"))}) " +

$"values({string.Join(",", type.GetProperties().Select(n => $"{f(n)}"))})";

MySqlCommand cmd = new MySqlCommand(sql,conn);

int result = cmd.ExecuteNonQuery();

conn.Close();

return result;

}

}

}

二、Dapper原生封装

dapper框架是给IDBConnection写了一些扩展方法,底层还是反射实现对象的关系映射。我们使用的时候只需要会用泛型即可。

using System;
using System.Collections.Generic;
using System.Data;
using System.Data.SqlClient;
using System.IO;
using System.Linq;
using System.Threading.Tasks;
using Dapper;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Configuration.Json; namespace Model

{

public class DapperHelper

{

static DapperHelper()

{

//ReloadOnChange = true 当appsettings.json被修改时重新加载

_dbConnection = new SqlConnection();

_dbConnection.ConnectionString = new ConfigurationBuilder()

.SetBasePath(Directory.GetCurrentDirectory())

.AddJsonFile("appsettings.json").Build().GetConnectionString("Default");

}
    private static readonly IDbConnection _dbConnection;

    #region Query
public async Task&lt;T&gt; QueryFirstOrDefaultAsync&lt;T&gt;(string sql, object param = null, IDbTransaction transaction = null,
int? commandTimeout = null, CommandType? commandType = null)
{
return await _dbConnection.QueryFirstOrDefaultAsync&lt;T&gt;(sql, param, transaction, commandTimeout, commandType);
}
public T QueryFirstOrDefault&lt;T&gt;(string sql, object param = null, IDbTransaction transaction = null,
int? commandTimeout = null, CommandType? commandType = null)
{
return _dbConnection.QueryFirstOrDefault&lt;T&gt;(sql, param, transaction, commandTimeout, commandType);
}
public async Task&lt;List&lt;T&gt;&gt; QueryAsync&lt;T&gt;(string sql, object param = null, IDbTransaction transaction = null,
int? commandTimeout = null, CommandType? commandType = null)
{
return (await _dbConnection.QueryAsync&lt;T&gt;(sql, param, transaction, commandTimeout, commandType)).ToList();
}
public List&lt;T&gt; Query&lt;T&gt;(string sql, object param = null, IDbTransaction transaction = null,
bool buffered = true, int? commandTimeout = null, CommandType? commandType = null)
{
return _dbConnection.Query&lt;T&gt;(sql, param, transaction, buffered, commandTimeout, commandType).ToList();
}
#endregion #region Excute
public Task&lt;int&gt; ExecuteAsync(string sql, object param = null, IDbTransaction transaction = null,
int? commandTimeout = null, CommandType? commandType = null)
{
return _dbConnection.ExecuteAsync(sql, param, transaction, commandTimeout, commandType);
}
public int Execute(string sql, object param = null, IDbTransaction transaction = null,
int? commandTimeout = null, CommandType? commandType = null)
{
return _dbConnection.Execute(sql, param, transaction, commandTimeout, commandType);
} #endregion
}

}

使用:

using Model;
using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Threading.Tasks; namespace dapperDemo

{

class Program

{

static async Task Main(string[] args)

{

#region 原生dapper封装

DapperHelper dapper = new DapperHelper();
        #region 查询集合

        Console.WriteLine("-----------------查询集合-------------------");
var students = await dapper.QueryAsync&lt;Student&gt;("select * from Student");
Console.WriteLine(JsonConvert.SerializeObject(students));
#endregion #region 单个查询
Console.WriteLine("-----------------单个查询-------------------");
string sql = "select * from student where StudentName=@StudentName";
var stu = await dapper.QueryFirstOrDefaultAsync&lt;Student&gt;(sql, new { StudentName = "小红帽" });
Console.WriteLine(JsonConvert.SerializeObject(stu));
#endregion #region 新增
Console.WriteLine("-----------------新增-------------------");
Student student = new Student()
{
Id = Guid.NewGuid(),
StudentName = "小红帽",
Sex = SexType.Male,
CreateTime = DateTime.Now,
IsDelete = false,
Birthday = DateTime.Now
};
string excuteSql = "insert into student(id,studentname,sex,createtime,isdelete,birthday)" +
" values(@Id,@StudentName,@Sex,@CreateTime,@IsDelete,@Birthday)";
var result = await dapper.ExecuteAsync(excuteSql, student);
Console.WriteLine(result);
#endregion #region 删除
Console.WriteLine("-----------------删除-------------------");
string deleteSql = "delete from student where studentname=@studentName";
var result = await dapper.ExecuteAsync(deleteSql, new {studentName = "小红帽"});
Console.WriteLine($"结果:{result}");
#endregion #region 修改
Console.WriteLine("-----------------修改-------------------");
string updateSql = "update student set studentname=@NewStudentName where studentName=@OldStudentName";
var result = await dapper.ExecuteAsync(updateSql, new {NewStudentName = "杜甫", OldStudentName = "李白" });
Console.WriteLine($"结果:{result}");
#endregion #endregion 原生dapper封装 }
}

}

三、Dapper的二次封装(基于上一个)

利用反射对Dapper进行二次封装:DapperSuperHelper<T>.cs,通过继承继承dapper的封装,我们可以即可用使用原始封装又可以使用通用的对单表的增删改查。

该封装可以实现对单个表的增删改查,以及分页查询,修改、删除、查询都是基于id查询,id支持任意类型。

注意:修改的时候建议先查出数据再执行修改,因为目前封装的代码无法实现只更改某个字段,暂时是全部更改,必填项必须有值。非必填,不传值,即为null。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Threading.Tasks; namespace Model

{

public class DapperSuperHelper<T>:DapperHelper

{

/// <summary>

/// 查询所有

/// </summary>

/// <returns></returns>

public async Task<List<T>> GetAllAsync()

{

var sql = $"select * from {typeof(T).Name}";

return await QueryAsync<T>(sql);

}

public List<T> GetAll()

{

var sql = $"select * from {typeof(T).Name}";

return Query<T>(sql);

}

/// <summary>

/// 按id查询

/// </summary>

/// <param name="id"></param>

/// <returns></returns>

public T Get(object id)

{

var sql = $"select * from {typeof(T).Name} where id=@Id";

return QueryFirstOrDefault<T>(sql, new {Id = id});

}
    public async Task&lt;T&gt; GetAsync(object id)
{
var sql = $"select * from {typeof(T).Name} where id=@Id";
return await QueryFirstOrDefaultAsync&lt;T&gt;(sql, new { Id = id });
}
/// &lt;summary&gt;
/// 新增
/// &lt;/summary&gt;
/// &lt;param name="t"&gt;&lt;/param&gt;
/// &lt;returns&gt;&lt;/returns&gt;
public async Task&lt;int&gt; InsertAsync(T t)
{
Type type = t.GetType();
var sql = $"insert into {type.Name}" +
$"({string.Join(",",type.GetProperties().Select(n=&gt;n.Name))})"+
$" values({string.Join(",",type.GetProperties().Select(n=&gt;$"@{n.Name}"))})";
return await ExecuteAsync(sql,t);
}
public int Insert(T t)
{
Type type = t.GetType();
var sql = $"insert into {type.Name}" +
$"({string.Join(",", type.GetProperties().Select(n =&gt; n.Name))})" +
$" values({string.Join(",", type.GetProperties().Select(n =&gt; $"@{n.Name}"))})";
return Execute(sql, t);
}
/// &lt;summary&gt;
/// 修改
/// &lt;/summary&gt;
/// &lt;param name="t"&gt;&lt;/param&gt;
/// &lt;returns&gt;&lt;/returns&gt;
public async Task&lt;int&gt; UpdateAsync(T t)
{
Type type = t.GetType();
var sql = $"update {type.Name} set " +
$"{string.Join(",", type.GetProperties().Select(n =&gt; $"{n.Name}=@{n.Name}"))} " +
$"where id=@Id";
return await ExecuteAsync(sql,t);
}
public int Update(T t)
{
Type type = t.GetType();
var sql = $"update {type.Name} set " +
$"{string.Join(",", type.GetProperties().Select(n =&gt; $"{n.Name}=@{n.Name}"))} " +
$"where id=@Id";
return Execute(sql, t);
}
/// &lt;summary&gt;
/// 按id删除
/// &lt;/summary&gt;
/// &lt;param name="id"&gt;&lt;/param&gt;
/// &lt;returns&gt;&lt;/returns&gt;
public async Task&lt;bool&gt; DeleteAsync(object id)
{
var sql = $"delete from {typeof(T).Name} where id=@Id";
return await ExecuteAsync(sql, new { Id = id }) &gt; 0;
} public bool Delete(object id)
{
var sql = $"delete from {typeof(T).Name} where id=@Id";
return Execute(sql, new { Id = id }) &gt; 0;
}
/// &lt;summary&gt;
/// 删除全部
/// &lt;/summary&gt;
/// &lt;returns&gt;&lt;/returns&gt;
public async Task&lt;bool&gt; DeleteAllAsync()
{
var sql = $"delete from {typeof(T).Name}";
return await ExecuteAsync(sql) &gt; 0;
} public bool DeleteAll()
{
var sql = $"delete from {typeof(T).Name}";
return Execute(sql) &gt; 0;
}
/// &lt;summary&gt;
/// 单表分页查询
/// &lt;/summary&gt;
/// &lt;param name="pageIndex"&gt;&lt;/param&gt;
/// &lt;param name="pageSize"&gt;&lt;/param&gt;
/// &lt;returns&gt;&lt;/returns&gt;
public async Task&lt;List&lt;T&gt;&gt; GetPagedAsync(int pageIndex,int pageSize)
{
var skipRow = (pageIndex - 1) * pageSize;
var sql = $"select * from {typeof(T).Name} order by Id " +
$"offset @skipRow rows fetch next @PageSize rows only";
return await QueryAsync&lt;T&gt;(sql, new {skipRow, pageSize});
}
/// &lt;summary&gt;
/// 单表分页查询
/// &lt;/summary&gt;
/// &lt;param name="pageIndex"&gt;&lt;/param&gt;
/// &lt;param name="pageSize"&gt;&lt;/param&gt;
/// &lt;returns&gt;&lt;/returns&gt;
public List&lt;T&gt; GetPaged(int pageIndex, int pageSize)
{
var skipRow = (pageIndex - 1) * pageSize;
var sql = $"select * from {typeof(T).Name} order by Id " +
$"offset @skipRow rows fetch next @PageSize rows only";
return Query&lt;T&gt;(sql, new { skipRow, pageSize });
}
}

}

使用:

using Model;
using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Threading.Tasks; namespace dapperDemo

{

class Program

{

static async Task Main(string[] args)

{
        #region dapper二次封装
DapperSuperHelper&lt;Student&gt; superDapper = new DapperSuperHelper&lt;Student&gt;();
//查询所有
List&lt;Student&gt; students = await superDapper.GetAllAsync();
Console.WriteLine(JsonConvert.SerializeObject(students)); //按id查询
var id = Guid.Parse("b2847592-90d6-40a4-b3b0-c1ebf514e258");
var stu = await superDapper.GetAsync(id);
Console.WriteLine(JsonConvert.SerializeObject(stu)); //新增
Student entity = new Student()
{
Id = Guid.NewGuid(),
Birthday = DateTime.Now,
CreateTime = DateTime.Now,
Email = "hello@163.com",
IsDelete = false,
Sex = SexType.Female,
StudentName = "夏花"
};
var result = await superDapper.InsertAsync(entity);
Console.WriteLine($"新增结果,受影响的行数:{result}"); //修改
entity.StudentName = "小燕子";
var updateResult = await superDapper.UpdateAsync(entity);
Console.WriteLine($"修改结果,受影响的行数:{updateResult}"); //删除
var did = Guid.Parse("b2847592-90d6-40a4-b3b0-c1ebf514e258");
var deleteResult = await superDapper.DeleteAsync(did);
Console.WriteLine($"删除结果:{deleteResult}"); //分页查询
var pagedResult = await superDapper.GetPagedAsync(2, 2);
Console.WriteLine(JsonConvert.SerializeObject(pagedResult));
#endregion }
}

}

四、Dapper官方提供的扩展包

原理和我通过反射进行的二次封装差不多,但是肯定比我写的更安全和规范、更复杂,不过官方的id我看了一下,好像只支持int类型。

可以看到我上面的二次封装和官方的封装其实差不多的功能,不过我还多了一个分页,嘿嘿。

using System.Collections.Generic;
using System.Data;
using System.Data.SqlClient;
using System.IO;
using System.Threading.Tasks;
using Dapper.Contrib.Extensions;
using Microsoft.Extensions.Configuration; namespace Model

{

public class DapperExtHelper<T> where T:class

{

static DapperExtHelper()

{

_dbConnection = new SqlConnection();

_dbConnection.ConnectionString = new ConfigurationBuilder()

.SetBasePath(Directory.GetCurrentDirectory())

.AddJsonFile("appsettings.json").Build().GetConnectionString("Default");

}
    private static readonly IDbConnection _dbConnection;

    public List&lt;T&gt; GetAll()
{
return _dbConnection.GetAll&lt;T&gt;().ToList();
}
public async Task&lt;List&lt;T&gt;&gt; GetAllAsync()
{
return (await _dbConnection.GetAllAsync&lt;T&gt;()).ToList();
}
public T Get(int id)
{
return _dbConnection.Get&lt;T&gt;(id);
} public bool Update(T entity)
{
return _dbConnection.Update(entity);
} public async Task&lt;bool&gt; UpdateAsync(T entity)
{
return await _dbConnection.UpdateAsync(entity);
}
public long Insert(T entity)
{
return _dbConnection.Insert(entity);
}
public async Task&lt;long&gt; InsertAsync(T entity)
{
return await _dbConnection.InsertAsync(entity);
} public bool Delete(T entity)
{
return _dbConnection.Delete(entity);
}
public async Task&lt;bool&gt; DeleteAsync(T entity)
{
return await _dbConnection.DeleteAsync(entity);
}
public bool DeleteAll()
{
return _dbConnection.DeleteAll&lt;T&gt;();
}
public async Task&lt;bool&gt; DeleteAllAsync()
{
return await _dbConnection.DeleteAllAsync&lt;T&gt;();
}
}

}

使用:

using Model;
using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Threading.Tasks; namespace dapperDemo

{

class Program

{

static async Task Main(string[] args)

{
        #region dapper官方自带的扩展包
//查全部,官方默认会以类名后面加个s,我们最好指定[Table("Student")]
DapperExtHelper&lt;Student&gt; dapperExtHelper = new DapperExtHelper&lt;Student&gt;();
var students = dapperExtHelper.GetAll();
Console.WriteLine(JsonConvert.SerializeObject(students));
//id查询 只支持id为int
//var stu = dapperExtHelper.Get(1);
//删除全部
//dapperExtHelper.DeleteAll();
//删除
var delEntity = new Student()
{
Id = Guid.Parse("c066dfce-d7cd-46b5-9fa3-d0aa4b165dde")
};
//dapperExtHelper.Delete(delEntity);
//修改 全部字段修改,需要传递必填的参数,否则报错,未传的参数修改为空,因此最好是先查出当实体,再修改单独字段
var updEntity = new Student()
{
Id = Guid.Parse("b2847592-90d6-40a4-b3b0-c1ebf514e257"),
StudentName = "李白222",
CreateTime = DateTime.Now,
Birthday = DateTime.Now
};
dapperExtHelper.Update(updEntity);
//新增 这居然报错,id不能传null,就离谱,估计和类型有关
Student InsertEntity = new Student()
{
Id = Guid.NewGuid(),
Birthday = DateTime.Now,
CreateTime = DateTime.Now,
Email = "hello@163.com",
IsDelete = false,
Sex = SexType.Female,
StudentName = "夏花"
};
dapperExtHelper.Insert(InsertEntity); #endregion
}
}

}

以上就是我对dapper的简单的封装。大家也可以自行封装。

需要源代码的可以加群831181779@群主哦

Dapper的封装、二次封装、官方扩展包封装,以及ADO.NET原生封装的更多相关文章

  1. [ Laravel 5.5 文档 ] 官方扩展包 —— 全文搜索解决方案:Laravel Scout

    简介 Laravel Scout 为 Eloquent 模型全文搜索实现提供了简单的.基于驱动的解决方案.通过使用模型观察者,Scout 会自动同步更新模型记录的索引. 目前,Scout 通过 Alg ...

  2. laravel中使用的PDF扩展包——laravel-dompdf和laravel-snappy

    这两天项目中需要将HTML页面转换为PDF文件方便打印,我在网上搜了很多资料.先后尝试了laravel-dompdf和laravel-snappy两种扩展包,个人感觉laravel-snappy比较好 ...

  3. MTK官方SDK包编译openwrt

    全过程需要联网,最好有梯子,编译方式有两种 安装依赖库: apt-get install g++ apt-get install libncurses5-dev apt-get install zli ...

  4. 孟老板 BaseAdapter封装 (二) Healer,footer

    BaseAdapter封装(一) 简单封装 BaseAdapter封装(二) Header,footer BaseAdapter封装(三) 空数据占位图 BaseAdapter封装(四) PageHe ...

  5. Dapper基础知识二

    在下刚毕业工作,之前实习有用到Dapper?这几天新项目想用上Dapper,在下比较菜鸟,这块只是个人对Dapper的一种总结. 2,如何使用Dapper?     首先Dapper是支持多种数据库的 ...

  6. Laravel5中通过SimpleQrCode扩展包生成二维码实例

    Simple Qrcode是基于强大的Bacon/BaconQrCode库开发的针对Laravel框架的封装版本,用于在Laravel中为生成二维码提供接口. 安装SimpleQrCode扩展包 在项 ...

  7. WinDbg 命令三部曲:(二)WinDbg SOS 扩展命令手册

    本文为 Dennis Gao 原创技术文章,发表于博客园博客,未经作者本人允许禁止任何形式的转载. 系列博文 <WinDbg 命令三部曲:(一)WinDbg 命令手册> <WinDb ...

  8. Windows下用Composer引入官方GitHub扩展包

    Windows下用Composer引入官方GitHub扩展包 1. 当你打开威武RC4版本的链接的时候,往下拉你可以看到这个,然后你要做的就是想到,百度Composer,看看是个什么鬼,别想太多,跟着 ...

  9. FreeSql 扩展包实现 Dapper 的使用习惯

    简介 FreeSql.Connection.Extensions 这是 FreeSql 衍生出来的扩展包,实现(Mysql/postgresql/sqlserver/Oracle/SQLite)数据库 ...

随机推荐

  1. 使用MySQL的SELECT INTO OUTFILE ,Load data file,Mysql 大量数据快速导入导出

    使用MySQL的SELECT INTO OUTFILE .Load data file LOAD DATA INFILE语句从一个文本文件中以很高的速度读入一个表中.当用户一前一后地使用SELECT ...

  2. python web框架学习笔记

    一.web框架本质 1.基于socket,自己处理请求 #!/usr/bin/env python3 #coding:utf8 import socket def handle_request(cli ...

  3. malloc() vs new

    Following are the differences between malloc() and operator new. (1)new calls constructors, while ma ...

  4. 【Service】【Database】【MySQL】基础概念

    1. 数据模型:层次模型.网状模型.关系模型 关系模型: 二维关系: 表:row, column 索引:index 视图:view 2. SQL接口:Structured Query Language ...

  5. springmvc中如何自定义类型转换器

    package com.hope.utils;import org.springframework.core.convert.converter.Converter;import org.spring ...

  6. 【科研工具】CAJViewer的一些操作

    逐渐发现CAJViewer没有想象中的难用. 添加书签:Ctrl+M 使用按类分类,可以筛选出书签位置,和注释区分. 搜索:Ctrl+F 可以定义多种搜索.

  7. 今天使用Bufferedrader ,单缓冲区的数据读取时出现的中文乱码的问题

    1.使用这种方式可能出现的中文乱码代码: /** * 第三套********:使用BufferReader,单缓冲区的数据读取和写入(字符输入流) * 读取 */ FileReader frFileR ...

  8. [BUUCTF]PWN——jarvisoj_test_your_memory

    jarvisoj_test_your_memory 附件 步骤: 例行检查,32位程序,开启了nx保护 试运行一下程序,看看大概的情况 32位ida打开,习惯性的检索程序里的字符串,看到了有关flag ...

  9. Birt报表设置自定义的值

    比如数据库查出该字段的值有"no",有"yes",那么想要根据当是no是显示"未完成",当是yes时显示"已完成" 可以 ...

  10. lightgallery 使用

    用途 图片预览,支持多图片滑动预览 git 地址 https://github.com/sachinchoolur/lightgallery.js 代码 # idnex.html <script ...