编写T4模板+DapperHelper（Sqlite数据库，简单更改即可适用其他数据库）==》简易ORM-简单的更有效更容易管理不容易出错

T4模板

<#@ template debug="false" hostspecific="false" language="C#" #>
<#@ output extension=".cs" #>
<#@ assembly name="System.Data" #>
<#@ assembly name="System.Data.SQLite" #>
<#@ import namespace="System.Data" #>
<#@ import namespace="System.Data.SQLite" #>
//------------------------------------------------------------------------------
//姜佳泉测试T4模板
//说明:与DapperHelper绑定使用，基础功能只有增删改，没有查询，没有分页。
//理由-->只作通用性，各数据库分页及高级查询语法各异，需要不同sql语句通过DapperHelper实现高级查询与分页
//特殊说明:id自增
//------------------------------------------------------------------------------
<#
//配置
  //连接数据库字符串SqlLite数据库
  string connectionString = "Data Source=C:\Users\jjq\Desktop\T4Test\WebApplication1\App_Data\student.db;Pooling=true;FailIfMissing=false";
  //指定表
  string tableName="students";
  //自增的主键
  string ID="id";
  //指定空间名
  string nameSpace="WebApplication1";
#>
<#
//连接数据库，获取表头
  SQLiteConnection connection = new SQLiteConnection(connectionString);
  DataSet ds = new DataSet();
  connection.Open();
  SQLiteDataAdapter command = new SQLiteDataAdapter("select * from "+tableName+"  WHERE 1 = 0 ", new SQLiteConnection(connectionString));
  command.Fill(ds, "ds");
  connection.Close();
#>
<#
//拼sql
string insertSql1="insert into "+tableName+"(";
string insertSql2=") values(";
string insertSql3=")";

string updateSql1="update "+tableName+" set ";
string updateSql2="";
string updateSql3=" where "+ID+"=@"+ID;
#>
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;

namespace <#=nameSpace#>
{
    public class <#=tableName#>
    {
<#
for (int i = 0; i < ds.Tables[0].Columns.Count; i++)
{
if (ds.Tables[0].Columns[i].DataType.Name.ToString()=="Int64"||ds.Tables[0].Columns[i].DataType.Name.ToString()=="Int32")
{
#>
        public int <#=ds.Tables[0].Columns[i].ColumnName#> { get; set; }
<#
}
else
{
#>
        public <#=ds.Tables[0].Columns[i].DataType.Name#> <#=ds.Tables[0].Columns[i].ColumnName#> { get; set; }
<#
}

if (ds.Tables[0].Columns[i].ColumnName!=ID)
{
insertSql1+=ds.Tables[0].Columns[i].ColumnName+",";
insertSql2+="@"+ds.Tables[0].Columns[i].ColumnName+",";
updateSql2+= ds.Tables[0].Columns[i].ColumnName+"="+"@"+ds.Tables[0].Columns[i].ColumnName+",";
}

}
string insertSql=insertSql1.Substring(0, insertSql1.Length - 1)+insertSql2.Substring(0, insertSql2.Length - 1)+insertSql3;
string deleteSql="delete from students where "+ID+"=@"+ID;
string updateSql=updateSql1+updateSql2.Substring(0, updateSql2.Length - 1)+updateSql3;

#>

        //新增
        public Message Insert()
        {
            Message mg = new Message();
            try
            {
                int RetNum = DapperHelper<<#=tableName#>>.Execute("<#=insertSql#>", this);
                if (RetNum == 1)
                {
                    mg.MessageResult = "Y";
                    mg.MessageContext = "新增成功";
                    return mg;
                }
                else
                {
                    mg.MessageContext = "新增失败";
                    return mg;
                }
            }
            catch (Exception ex)
            {
                mg.MessageContext = "Exception，严重错误！";
                return mg;
            }
        }
        //删除
        public Message Delete()
        {
            Message mg = new Message();
            try
            {
                int RetNum = DapperHelper<<#=tableName#>>.Execute("<#=deleteSql#>", this);
                if (RetNum == 1)
                {
                    mg.MessageResult = "Y";
                    mg.MessageContext = "删除成功";
                    return mg;
                }
                else
                {
                    mg.MessageContext = "删除失败";
                    return mg;
                }
            }
            catch (Exception ex)
            {
                mg.MessageContext = "Exception，严重错误！";
                return mg;
            }
        }
        //更新
        public Message Update()
        {
            Message mg = new Message();
            try
            {
                int RetNum = DapperHelper<<#=tableName#>>.Execute("<#=updateSql#>", this);
                if (RetNum == 1)
                {
                    mg.MessageResult = "Y";
                    mg.MessageContext = "更新成功";
                    return mg;
                }
                else
                {
                    mg.MessageContext = "更新失败";
                    return mg;
                }
            }
            catch (Exception ex)
            {
                mg.MessageContext = "Exception，严重错误！";
                return mg;
            }
        }
     }
     //返回信息
    public class Message
    {
        private string messageResult = "N";
        private string messageContext;
        /// <summary>
        /// 返回的结果（Y,N）
        /// </summary>
        public string MessageResult
        {
            set { messageResult = value; }
            get { return messageResult; }
        }
        /// <summary>
        /// 提示内容
        /// </summary>
        public string MessageContext
        {
            set { messageContext = value; }
            get { return messageContext; }
        }

    }
}

T4模板产品（测试可用）

//------------------------------------------------------------------------------
//姜佳泉测试T4模板
//说明:与DapperHelper绑定使用，基础功能只有增删改，没有查询，没有分页。
//理由-->只作通用性，各数据库分页及高级查询语法各异，需要不同sql语句通过DapperHelper实现高级查询与分页
//特殊说明:id自增
//------------------------------------------------------------------------------
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;

namespace WebApplication1
{
    public class students
    {
        public int id { get; set; }
        public String name { get; set; }
        public String address { get; set; }

        //新增
        public Message Insert()
        {
            Message mg = new Message();
            try
            {
                int RetNum = DapperHelper<students>.Execute("insert into students(name,address) values(@name,@address)", this);
                if (RetNum == 1)
                {
                    mg.MessageResult = "Y";
                    mg.MessageContext = "新增成功";
                    return mg;
                }
                else
                {
                    mg.MessageContext = "新增失败";
                    return mg;
                }
            }
            catch (Exception ex)
            {
                mg.MessageContext = "Exception，严重错误！";
                return mg;
            }
        }
        //删除
        public Message Delete()
        {
            Message mg = new Message();
            try
            {
                int RetNum = DapperHelper<students>.Execute("delete from students where id=@id", this);
                if (RetNum == 1)
                {
                    mg.MessageResult = "Y";
                    mg.MessageContext = "删除成功";
                    return mg;
                }
                else
                {
                    mg.MessageContext = "删除失败";
                    return mg;
                }
            }
            catch (Exception ex)
            {
                mg.MessageContext = "Exception，严重错误！";
                return mg;
            }
        }
        //更新
        public Message Update()
        {
            Message mg = new Message();
            try
            {
                int RetNum = DapperHelper<students>.Execute("update students set name=@name,address=@address where id=@id", this);
                if (RetNum == 1)
                {
                    mg.MessageResult = "Y";
                    mg.MessageContext = "更新成功";
                    return mg;
                }
                else
                {
                    mg.MessageContext = "更新失败";
                    return mg;
                }
            }
            catch (Exception ex)
            {
                mg.MessageContext = "Exception，严重错误！";
                return mg;
            }
        }
     }
     //返回信息
    public class Message
    {
        private string messageResult = "N";
        private string messageContext;
        /// <summary>
        /// 返回的结果（Y,N）
        /// </summary>
        public string MessageResult
        {
            set { messageResult = value; }
            get { return messageResult; }
        }
        /// <summary>
        /// 提示内容
        /// </summary>
        public string MessageContext
        {
            set { messageContext = value; }
            get { return messageContext; }
        }

    }
}

DapperHelper

using Dapper;
using System;
using System.Collections.Generic;
using System.Configuration;
using System.Data;
using System.Data.SQLite;
using System.Linq;

namespace WebApplication1
{
    public class DapperHelper<T>
    {
        //说明：更换SQLiteConnection与using System.Data.SQLite即可更换其他数据库
        /// <summary>
        /// 数据库连接字符串
        /// </summary>
        private static readonly string connectionString = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;

        /// <summary>
        /// 查询返回列表List《T》
        /// .QueryToList("select * from students where id=@id and name=@name", new { id = 1 ,name= "张小花" })
        /// </summary>
        /// <param name="sql">查询的sql</param>
        /// <param name="param">替换参数</param>
        /// <returns></returns>

        public static List<T> QueryToList(string sql, object param = null)
        {
            using (SQLiteConnection con = new SQLiteConnection(connectionString))
            {
                return con.Query<T>(sql, param).ToList();
            }
        }

        /// <summary>
        /// 查询返回DataTable
        /// .QueryToTable("select * from students where id=???常规sql语句")
        /// </summary>
        /// <param name="sql">查询的sql</param>
        /// <param name="param">替换参数</param>
        /// <returns></returns>

        public static DataTable QueryToTable(string sql, object param = null)
        {
            using (SQLiteConnection con = new SQLiteConnection(connectionString))
            {
                DataTable dt = new DataTable();
                var reader = con.ExecuteReader(sql);
                dt.Load(reader);
                return dt;
            }
        }

        /// <summary>
        /// 查询第一个数据,返回一个实体T
        /// </summary>
        /// <param name="sql"></param>
        /// <param name="param"></param>
        /// <returns></returns>
        public static T QueryFirstOrNull(string sql, object param = null)
        {
            using (SQLiteConnection con = new SQLiteConnection(connectionString))
            {
                return con.Query<T>(sql, param).ToList().SingleOrDefault();
            }
        }

        /// <summary>
        /// 执行single-增删改-("insert/delete/update T_User set username=@username where uid=@uid", new { username = "李四", uid = 1})
        /// </summary>
        /// <param name="sql"></param>
        /// <param name="param"></param>
        /// <returns>执行影响行数 int 0or1</returns>
        public static int Execute(string sql, object param)
        {
            using (SQLiteConnection con = new SQLiteConnection(connectionString))
            {
                return con.Execute(sql, param);
            }
        }

        /// <summary>
        /// 执行many-增删改-("insert/delete/update T_User set username=@username where uid=@uid", List《T》)
        /// </summary>
        /// <param name="sql"></param>
        /// <param name="param"></param>
        /// <returns>执行影响行数 int 0or1+</returns>
        /// List<students> listStu = new List<students>();
        public static int ExecuteList(string sql, List<T> t)
        {
            //  listStu.Add(new students { id = 1, name = "新1", address = "年1" });
            //  listStu.Add(new students { id = 2, name = "快1", address = "乐1" });
            //  var a = DapperHelper<students>.ExecuteList("update students set name = @name, address = @address where id=@id", listStu);
            using (SQLiteConnection con = new SQLiteConnection(connectionString))
            {
                return con.Execute(sql, t);
            }
        }

        /// <summary>
        /// 无参事务-List《stringSql》
        /// </summary>
        /// <param name="sqlarr">多条SQL</param>
        /// <param name="param">param</param>
        /// <returns></returns>
        public static int ExecuteTransaction(List<string> sqlList)
        {
            using (SQLiteConnection con = new SQLiteConnection(connectionString))
            {                    
                con.Open();//在dapper中使用事务，需要手动打开连接
                using (var transaction = con.BeginTransaction())
                {
                    try
                    {
                        int result = 0;
                        foreach (var sql in sqlList)
                        {
                            result += con.Execute(sql, null, transaction);
                        }

                        transaction.Commit();
                        con.Close();//在dapper中使用事务，需要手动关闭连接
                        return result;
                    }
                    catch (Exception ex)
                    {
                        transaction.Rollback();
                        con.Close();//在dapper中使用事务，需要手动关闭连接
                        return 0;
                    }
                }

            }
        }

        /// <summary>
        /// 带参事务-Dictionary.Add（"Insert into Users values (@UserName, @Email, @Address)"，new { UserName = "jack", Email = "380234234@qq.com", Address = "上海" })
        /// </summary>
        /// <param name="dic"></param>
        /// <returns></returns>
        public static int ExecuteTransactionDic(Dictionary<string, T> dic)
        {
           //Dictionary<string, students> dic = new Dictionary<string, students>();
           //dic.Add("delete from students where id=@id", new students { id = 1 });
           //dic.Add("delete from students where id=@id ", new students { id = 2 });
            using (SQLiteConnection con = new SQLiteConnection(connectionString))
            {
                con.Open();//在dapper中使用事务，需要手动打开连接
                using (var transaction = con.BeginTransaction())
                {
                    try
                    {
                        int result = 0;
                        foreach (var param in dic)
                        {
                            result += con.Execute(param.Key, param.Value, transaction);
                        }
                        transaction.Commit();
                        con.Close();//在dapper中使用事务，需要手动关闭连接

                        return result;
                    }
                    catch (Exception ex)
                    {
                        transaction.Rollback();
                        con.Close();//在dapper中使用事务，需要手动关闭连接
                        return 0;
                    }
                }
            }
        }

    }
}