通过反射来手写简单的ORM SQlserver

不说废话，直接上干货，如发现问题，欢迎大家指出，谢谢！

//------------------------------------MySQlServerORM 【简单 CURD】

using System;
using System.Collections.Generic;
using System.Linq;
namespace COMMOM
{
using C10.ZRF.Model.Filter;
using System.Configuration;
using System.Data.SqlClient;
using Dapper;
using System.Reflection;
using static COMMOM.SqlEnum;

public static class MySQlServerORM
{
private static readonly string con = ConfigurationManager.ConnectionStrings["sqlc"].ConnectionString;

#region 查询单个实体 T GetEntityByID<T>(int id)
public static T GetEntityByID<T>(int id) where T : class, new()
{
string pkName = ReflectionAttriHelper.GetPrimaryKey(typeof(T));
string sql = SuperSQlGet<T>.GetSQL(SQLType.GetEntityByID_SQL);
using (SqlConnection conn = new SqlConnection(con))
{
DynamicParameters parem = new DynamicParameters();
parem.Add(pkName, id);
T result = conn.QueryAsync<T>(sql, parem).Result.FirstOrDefault();
return result ?? default(T);
}
}
#endregion

#region 查询一张表的所有集合数据 IEnumerable<T> GetAllList<T>()
public static List<T> GetAllList<T>() where T : class, new()
{
string sql = SuperSQlGet<T>.GetSQL(SQLType.GetAllList_SQL);
using (SqlConnection conn = new SqlConnection(con))
{
return (conn.QueryAsync<T>(sql).Result.ToList()) ?? default(List<T>);
}
}
#endregion

#region 新增 bool Insert<T>(T entity)
public static bool Insert<T>(T entity) where T : class,new()
{
string sql = SuperSQlGet<T>.GetSQL(SQLType.Insert_SQl);
PropertyInfo[] pylist = typeof(T).GetProperties().IgnorePKID();
using (SqlConnection conn = new SqlConnection(con))
{
DynamicParameters pa = new DynamicParameters();
pylist.ToList().ForEach(p => { pa.Add($"{p.Name}", p.GetValue(entity)); });
return conn.ExecuteAsync(sql,pa).Result > 0 ? true : false;
}
}
#endregion

#region 删除操作DeleteByPrimaryKey<T>(int id)
public static bool DeleteByPrimaryKey<T>(int id) where T : class, new()
{
string sql = SuperSQlGet<T>.GetSQL(SQLType.DeleteByPrimaryKey_SQL);
using (SqlConnection conn = new SqlConnection(con))
{
DynamicParameters parameters = new DynamicParameters();
parameters.Add(ReflectionAttriHelper.GetPrimaryKey(typeof(T)), id);
return conn.ExecuteAsync(sql, parameters).Result > 0;
}
}
//删除操作DeleteByEntity<T>(T entity)
public static bool DeleteByEntity<T>(T entity) where T : class, new()
{
if (entity != null)
{
try
{
Type ty = entity.GetType();
object obj = null;
// ty.GetProperties().Any(c =>..... 两个都可以，还是使用下面的防止报错，效率也高些
ty.GetProperties().FirstOrDefault(c =>
{
if (c.IsDefined(typeof(PKAttribute)))
{
obj = c.GetValue(entity); return true;
}
else { return false; }
});
return obj != null ? DeleteByPrimaryKey<T>(int.Parse(obj.ToString())) : false;
}
catch (Exception ex) { throw new Exception("删除操作失败，原因：" + ex.Message); }
}
return false;
}
#endregion
}
}

//--------------------------------------SuperSQlGet<T> 静态构造函数来初始化SQL语句 【获取SQL语句】
using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;
using static COMMOM.SqlEnum;

namespace COMMOM
{
public static class SuperSQlGet<T> where T : class, new()
{
private static string GetEntityByID_SQL = string.Empty;
private static string GetAllList_SQL = string.Empty;
private static string Insert_SQl = string.Empty;
private static string DeleteByPrimaryKey_SQL = string.Empty;

static SuperSQlGet()
{
//-----------1GetEntityByID
Type ty = typeof(T);
string pkName = ReflectionAttriHelper.GetPrimaryKey(ty);
GetEntityByID_SQL = $"select top 1 * from [{ReflectionAttriHelper.GetTBName(ty)}] where {pkName}[email protected]{pkName}";

//-----------2 GetAllList
GetAllList_SQL = $"select * from [{ReflectionAttriHelper.GetTBName(ty)}] ";

//------------3 insert
PropertyInfo[] pylist = ty.GetProperties().IgnorePKID();
string tabPro = string.Join(",", pylist.Select(c => $"{c.Name}"));
string vastrSafe = string.Join(",", pylist.Select(c => $"@{c.Name}"));
Insert_SQl = $"insert into [{ReflectionAttriHelper.GetTBName(ty)}]({tabPro}) values({vastrSafe})";

//----------4 DeleteByPrimaryKey
DeleteByPrimaryKey_SQL = $"delete from [{ReflectionAttriHelper.GetTBName(ty)}] where {pkName}[email protected]{pkName}";
}

public static string GetSQL(SQLType sqltype)
{
switch (sqltype)
{
case SQLType.GetEntityByID_SQL: return GetEntityByID_SQL;
case SQLType.GetAllList_SQL: return GetAllList_SQL;
case SQLType.Insert_SQl: return Insert_SQl;
case SQLType.DeleteByPrimaryKey_SQL: return DeleteByPrimaryKey_SQL;
default:
throw new Exception("SQl获取异常.....");
}
}
}
}

//----------------------------SqlEnum 【生成SQL使用的枚举】
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace COMMOM
{
public static class SqlEnum
{
public enum SQLType
{
GetEntityByID_SQL,
GetAllList_SQL,
Insert_SQl,
DeleteByPrimaryKey_SQL
}
}
}

//---------------------------------------ReflectionAttriHelper 【帮助类】
using C10.ZRF.Model.Filter;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;

namespace COMMOM
{
public static class ReflectionAttriHelper
{
#region GetPrimaryKey(Type ty) 获取主键的属性
public static string GetPrimaryKey(Type ty)
{
var prolist = ty.GetProperties();
string proName = string.Empty;
prolist.FirstOrDefault(c =>
{
if (c.IsDefined(typeof(PKAttribute), false))
{
proName = c.Name; return true;
}
else { return false; }
});
return !string.IsNullOrEmpty(proName) ? proName : "id";
}
#endregion

#region 获取表的映射名称 string GetTBName(Type type)
public static string GetTBName(Type type)
{
Type ty = typeof(TabNameAttribute);
return type.IsDefined(ty) ? ((TabNameAttribute)type.GetCustomAttribute(ty, false)).name : type.Name;
}
#endregion

#region 去掉主键的属性 PropertyInfo[] IgnorePKID(this PropertyInfo[] py )
public static PropertyInfo[] IgnorePKID(this PropertyInfo[] py)
{
List<PropertyInfo> pylist = new List<PropertyInfo>();
py.ToList().ForEach(c => { if (!c.IsDefined(typeof(PKAttribute))) pylist.Add(c); });
return pylist.ToArray();
}
#endregion
}
}

//---------------------------Filter 【过滤器及Attribute】
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace C10.ZRF.Model.Filter
{
using System.Reflection;
[AttributeUsage(AttributeTargets.Class)]
public class TabNameAttribute : Attribute
{
public string name { get; set; }
public TabNameAttribute(string tabName)
{
this.name = tabName;
}
}

[AttributeUsage(AttributeTargets.Property)]
public class PKAttribute : Attribute
{
}

[AttributeUsage(AttributeTargets.Property)]
public class ProNameAttribute : Attribute
{
public string pname { get; set; }
public ProNameAttribute(string pname)
{
this.pname = pname;
}
}
}

//-------------------model【实体】
using System;
namespace C10.ZRF.Model.ModelView
{
using Filter;
[TabName("User")]
public class UserView
{
[PK]
public int uid { get; set; }
public string userName { get; set; }
public string userPwd { get; set; }
public string userPhone { get; set; }
public int? userAge { get; set; }
public bool isdel { get; set; }
[ProName("creatime")]
public DateTime? addTime { get; set; }
public override string ToString()
{
return $"uid={this.uid},userName={this.userName},userPwd={this.userPwd},userPhone={this.userPhone},userAge={this.userAge},";
}
}
}

//-----------------------UI 【显示的界面】
#region ORM
public ActionResult GetEntityByID()
{
UserView obj = MySQlServerORM.GetEntityByID<UserView>(6);
List<UserView> ulist = MySQlServerORM.GetAllList<UserView>();
ViewBag.objinfo =obj==null?"没有查找到": $"uid={obj.uid},姓名={obj.userName},TEL={obj.userPhone}";
string str = string.Empty;
ulist.ForEach(c => { str += (c.ToString() + "<br/>"); });
ViewBag.list = str;
return View();
}

public ActionResult AddEntity()
{ //------参数需要全部提供 需要参数 ‘@userName‘，但未提供该参数
bool flag = MySQlServerORM.Insert<UserView>(new UserView()
{
addTime = DateTime.Now,
isdel = false,
userAge = 19,
userName = "qqAdd",
userPhone = "182191777668",
userPwd = "pwd123"
});
ViewBag.addflag = flag ? "Addok" : "AddError";
return View();
}

public ActionResult DeleteORM()
{
// string deleteResult= MySQlServerORM.DeleteByPrimaryKey<UserView>(5) ? "成功" : "失败";//--根据PK来删除
UserView obj = new UserView { uid = 22 };
//--------根据实体来删除
string deleteResult = MySQlServerORM.DeleteByEntity<UserView>(obj) ? "成功" : "失败";
ViewBag.deleteok = $"数据删除{deleteResult}";
return View();
}
#endregion

原文地址：https://www.cnblogs.com/Fengge518/p/11725522.html