C#中Dapper的使用教程

Dapper是一款轻量级ORM工具（Github），Dapper语法十分简单。并且无须迁就数据库的设计，今天通过本文给大家介绍C# Dapper的使用，感兴趣的朋友一起看看吧

Dapper是一款轻量级ORM工具（Github）。如果你在小的项目中，使用Entity Framework、NHibernate 来处理大数据访问及关系映射，未免有点杀鸡用牛刀。你又觉得ORM省时省力，这时Dapper 将是你不二的选择。

1. 轻量。只有一个文件SqlMapper.cs，编译后就40K的一个很小的Dll.
2. 速度快。Dapper的速度接近与IDataReader，取列表的数据超过了DataTable。
3. 支持多种数据库。Dapper可以在所有Ado.net Providers下工作，包括sqlite, sqlce, firebird, oracle, MySQL, PostgreSQL and SQL Server
4. 可以映射一对一，一对多，多对多等多种关系。
5. 性能高。通过Emit反射IDataReader的序列队列，来快速的得到和产生对象，性能不错。
6. 支持FrameWork2.0，3.0，3.5，4.0，4.5
7. Dapper语法十分简单。并且无须迁就数据库的设计

8. // <copyright file="DapperTools.cs" company="PlaceholderCompany">
   // Copyright (c) PlaceholderCompany. All rights reserved.
   // </copyright>
   
   namespace CSharpStudy
   {
       using System;
       using System.Collections.Generic;
       using System.Configuration;
       using System.Data;
       using System.Data.SqlClient;
       using System.Linq;
       using System.Text;
       using System.Threading.Tasks;
       using Dapper;
   
       internal class DapperTools
       {
           public static string ConnectionString = ConfigurationManager.ConnectionStrings["MyStrConn"].ConnectionString;
   
           /// <summary>
           /// 添加.
           /// </summary>
           /// <typeparam name="T">实体类型.</typeparam>
           /// <param name="sql">传入sql执行语句.</param>
           /// <param name="t">传入实体类型.</param>
           /// <returns>int.</returns>
           public static int Add<T>(string sql, T t)
               where T : class
           {
               using (IDbConnection connection = new SqlConnection(ConnectionString))
               {
                   return connection.Execute(sql, t);
               }
           }
   
           /// <summary>
           /// 批量添加.
           /// </summary>
           /// <typeparam name="T">实体类型.</typeparam>
           /// <param name="sql">传入sql执行语句.</param>
           /// <param name="t">传入泛型类.</param>
           /// <returns>int.</returns>
           public static int Add<T>(string sql, List<T> t)
               where T : class
           {
               using (IDbConnection connection = new SqlConnection(ConnectionString))
               {
                   return connection.Execute(sql, t);
               }
           }
   
           /// <summary>
           /// 删除.
           /// </summary>
           /// <typeparam name="T">实体类型.</typeparam>
           /// <param name="sql">传入sql执行语句.</param>
           /// <param name="t">传入实体类型.</param>
           /// <returns>int.</returns>
           public static int Delete<T>(string sql, T t)
                 where T : class
           {
               using (IDbConnection connection = new SqlConnection(ConnectionString))
               {
                   return connection.Execute(sql, t);
               }
           }
   
           /// <summary>
           /// 批量删除.
           /// </summary>
           /// <typeparam name="T">实体类型.</typeparam>
           /// <param name="sql">传入sql执行语句.</param>
           /// <param name="t">传入泛型类.</param>
           /// <returns>int.</returns>
           public static int Delete<T>(string sql, List<T> t)
                 where T : class
           {
               using (IDbConnection connection = new SqlConnection(ConnectionString))
               {
                   return connection.Execute(sql, t);
               }
           }
   
           /// <summary>
           /// 修改.
           /// </summary>
           /// <typeparam name="T">实体类型.</typeparam>
           /// <param name="sql">传入sql执行语句.</param>
           /// <param name="t">传入实体类型.</param>
           /// <returns>int.</returns>
           public static int Update<T>(string sql, T t)
                 where T : class
           {
               using (IDbConnection connection = new SqlConnection(ConnectionString))
               {
                   return connection.Execute(sql, t);
               }
           }
   
           /// <summary>
           /// 批量修改.
           /// </summary>
           /// <typeparam name="T">实体类型.</typeparam>
           /// <param name="sql">传入sql执行语句.</param>
           /// <param name="t">传入泛型类.</param>
           /// <returns>int.</returns>
           public static int Update<T>(string sql, List<T> t)
                 where T : class
           {
               using (IDbConnection connection = new SqlConnection(ConnectionString))
               {
                   return connection.Execute(sql, t);
               }
           }
   
           /// <summary>
           /// 查询.
           /// </summary>
           /// <typeparam name="T">实体类型.</typeparam>
           /// <param name="sql">传入sql执行语句.</param>
           /// <returns>泛型类.</returns>
           public static List<T> Query<T>(string sql)
                where T : class
           {
               using (IDbConnection connection = new SqlConnection(ConnectionString))
               {
                   return connection.Query<T>(sql).ToList();
               }
           }
   
           /// <summary>
           /// 查询指定数据.
           /// </summary>
           /// <typeparam name="T">实体类型.</typeparam>
           /// <param name="sql">传入sql执行语句.</param>
           /// <param name="t">传入泛型类.</param>
           /// <returns>类.</returns>
           public static T Query<T>(string sql, T t)
                where T : class
           {
               using (IDbConnection connection = new SqlConnection(ConnectionString))
               {
                   return connection.Query<T>(sql, t).SingleOrDefault();
               }
           }
   
           /// <summary>
           /// 查询的in操作.
           /// </summary>
           /// <typeparam name="T">实体类型.</typeparam>
           /// <param name="sql">传入sql执行语句.</param>
           /// <returns>泛型类.</returns>
           public static List<T> Query<T>(string sql, int[] ids)
               where T : class
           {
               using (IDbConnection connection = new SqlConnection(ConnectionString))
               {
                   return connection.Query<T>(sql, new { ids }).ToList();
               }
           }
   
           /// <summary>
           /// 多语句操作.
           /// </summary>
           /// <typeparam name="T">实体类型.</typeparam>
           /// <param name="sql">传入sql执行语句.</param>
           public static void QueryMultiple(string sql)
           {
               using (IDbConnection connection = new SqlConnection(ConnectionString))
               {
                   var multiReader = connection.QueryMultiple(sql);
                   var userInfo = multiReader.Read<UserInfo>();
                   var student = multiReader.Read<Student>();
   
                   multiReader.Dispose();
               }
           }
       }
   }

   调用举例