自己整理了一个 Dapper的Helper助手类

链接字符串配置：#

<connectionStrings>
    <add name="db" connectionString="server=.;database=db;uid=sa;pwd=123456;integrated security=false;"/>
  </connectionStrings>

DapperHelper.cs :#

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using Dapper; 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;   namespace PullChargeData.Helper {     public class DapperHelper<T>     {         /// <summary>         /// 数据库连接字符串         /// </summary>         private static readonly string connectionString = ConfigurationManager.ConnectionStrings["db"].ConnectionString;           /// <summary>         /// 查询列表（返回DataTable）         /// </summary>         /// <returns></returns>         public static DataTable QueryToDataTable(string sql)         {             DataTable table = new DataTable("MyTable");             using (SqlConnection con = new SqlConnection(connectionString))             {                 var reader = con.ExecuteReader(sql);                 table.Load(reader);                 return table;             }         }           /// <summary>         /// 查询列表         /// </summary>         /// <param name="sql">查询的sql</param>         /// <param name="param">替换参数</param>         /// <returns></returns>         public static List<T> Query(string sql, object param = null)         {             using (SqlConnection con = new SqlConnection(connectionString))             {                 return con.Query<T>(sql, param).ToList();             }         }           /// <summary>         /// 查询第一个数据         /// </summary>         /// <param name="sql"></param>         /// <param name="param"></param>         /// <returns></returns>         public static T QueryFirst(string sql, object param = null)         {             using (SqlConnection con = new SqlConnection(connectionString))             {                 return con.Query<T>(sql, param).ToList().First();             }         }           /// <summary>         /// 查询第一个数据没有返回默认值         /// </summary>         /// <param name="sql"></param>         /// <param name="param"></param>         /// <returns></returns>         public static T QueryFirstOrDefault(string sql, object param = null)         {             using (SqlConnection con = new SqlConnection(connectionString))             {                 return con.Query<T>(sql, param).ToList().FirstOrDefault();             }         }           /// <summary>         /// 查询单条数据         /// </summary>         /// <param name="sql"></param>         /// <param name="param"></param>         /// <returns></returns>         public static T QuerySingle(string sql, object param = null)         {             using (SqlConnection con = new SqlConnection(connectionString))             {                 return con.Query<T>(sql, param).ToList().Single();             }         }           /// <summary>         /// 查询单条数据没有返回默认值         /// </summary>         /// <param name="sql"></param>         /// <param name="param"></param>         /// <returns></returns>         public static T QuerySingleOrDefault(string sql, object param = null)         {             using (SqlConnection con = new SqlConnection(connectionString))             {                 return con.Query<T>(sql, param).ToList().SingleOrDefault();             }         }           /// <summary>         /// 增删改         /// </summary>         /// <param name="sql"></param>         /// <param name="param"></param>         /// <returns>Number of rows affected</returns>         public static int Execute(string sql, object param)         {             using (SqlConnection con = new SqlConnection(connectionString))             {                 return con.Execute(sql, param);             }         }           /// <summary>         /// Reader获取数据         /// </summary>         /// <param name="sql"></param>         /// <param name="param"></param>         /// <returns></returns>         public static IDataReader ExecuteReader(string sql, object param)         {             using (SqlConnection con = new SqlConnection(connectionString))             {                 return con.ExecuteReader(sql, param);             }         }           /// <summary>         /// Scalar获取数据         /// </summary>         /// <param name="sql"></param>         /// <param name="param"></param>         /// <returns></returns>         public static object ExecuteScalar(string sql, object param)         {             using (SqlConnection con = new SqlConnection(connectionString))             {                 return con.ExecuteScalar(sql, param);             }         }           /// <summary>         /// Scalar获取数据         /// </summary>         /// <param name="sql"></param>         /// <param name="param"></param>         /// <returns></returns>         public static T ExecuteScalarForT(string sql, object param)         {             using (SqlConnection con = new SqlConnection(connectionString))             {                 return con.ExecuteScalar<T>(sql, param);             }         }           /// <summary>         /// 带参数的存储过程         /// </summary>         /// <param name="sql"></param>         /// <param name="param"></param>         /// <returns></returns>         public static List<T> ExecutePro(string proc, object param)         {             using (SqlConnection con = new SqlConnection(connectionString))             {                 List<T> list = con.Query<T>(proc,                     param,                     null,                     true,                     null,                     CommandType.StoredProcedure).ToList();                 return list;             }         }             /// <summary>         /// 事务1 - 全SQL         /// </summary>         /// <param name="sqlarr">多条SQL</param>         /// <param name="param">param</param>         /// <returns></returns>         public static int ExecuteTransaction(string[] sqlarr)         {             using (SqlConnection con = new SqlConnection(connectionString))             {                 using (var transaction = con.BeginTransaction())                 {                     try                     {                         int result = 0;                         foreach (var sql in sqlarr)                         {                             result += con.Execute(sql, null, transaction);                         }                           transaction.Commit();                         return result;                     }                     catch (Exception ex)                     {                         transaction.Rollback();                         return 0;                     }                 }             }         }           /// <summary>         /// 事务2 - 声明参数         ///demo:         ///dic.Add("Insert into Users values (@UserName, @Email, @Address)",         ///        new { UserName = "jack", Email = "380234234@qq.com", Address = "上海" });         /// </summary>         /// <param name="Key">多条SQL</param>         /// <param name="Value">param</param>         /// <returns></returns>         public static int ExecuteTransaction(Dictionary<string, object> dic)         {             using (SqlConnection con = new SqlConnection(connectionString))             {                 using (var transaction = con.BeginTransaction())                 {                     try                     {                         int result = 0;                         foreach (var sql in dic)                         {                             result += con.Execute(sql.Key, sql.Value, transaction);                         }                           transaction.Commit();                         return result;                     }                     catch (Exception ex)                     {                         transaction.Rollback();                         return 0;                     }                 }             }         }     } }

 

调用方法#

//查 无参数
var list = DapperHelper<T_User>.Query("select * from T_User ").ToList();
//查 带参数
var list = DapperHelper<T_User>.Query("select * from T_User where uid=@uid", new { uid = 1, }).ToList();
//增
int ins = DapperHelper<T_User>.Execute("insert into T_User (uid,username) value(@uid,@username)", new { uid = 1, username = "张三" });
//改
int upd = DapperHelper<T_User>.Execute("update T_User set username=@username where uid=@uid", new { username = "李四", uid = 1});
//删
int del = DapperHelper<T_User>.Execute("delete from T_User where uid=@uid", new { uid = 1 });