C#抽象增删改怎么实现
本篇内容主要讲解"C#抽象增删改怎么实现"，感兴趣的朋友不妨来看看。本文介绍的方法操作简单快捷，实用性强。下面就让小编来带大家学习"C#抽象增删改怎么实现"吧!
现在业界火了一种ORM 框架，那就是Dapper，我也是Dapper的粉丝之一，而我总结出来的框架也是基于Daaper。下面是我的代码，首先是Dapper Helper类，数据库通用访问类（用Nuget工具先把Dapper类引用到NetUtility.Dapper.Core项目中去）：
NetUtility.Dapper.Core.DataBaseAccess.cs
using System;
using System.Collections.Generic;
using System.Configuration;
using System.Data.SqlClient;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Dapper;
using System.Data;
using NetUtility.Entity;
using System.Reflection;
namespace NetUtility.Dapper.Core
{
///
/// 数据库访问类
///
public class DataBaseAccess
{
public static SqlConnection CreateConnection()
{
string connStr = ConfigurationManager.ConnectionStrings["connString"].ConnectionString;
SqlConnection conn = new SqlConnection(connStr);
conn.Open();
return conn;
}
///
/// 执行增、删、改方法
///
///
///
///
public static int Execute(string sql, object parms = null)
{
using (IDbConnection conn = CreateConnection())
{
return conn.Execute(sql,parms);
}
}
///
/// 得到单行单列
///
///
///
///
public static object ExecuteScalar(string sql, object parms = null)
{
using (IDbConnection conn = CreateConnection())
{
return conn.ExecuteScalar(sql, parms);
}
}
///
/// 单个数据集查询
///
///
///
///
public static List
Query (string sql,Func {
using (IDbConnection conn = CreateConnection())
{
return conn.Query
(sql, parms).Where(pre).ToList(); }
}
///
/// 单个数据集查询
///
///
///
///
public static List
Query (string sql, object parms = null) {
using (IDbConnection conn = CreateConnection())
{
return conn.Query
(sql, parms).ToList(); }
}
///
/// 多个数据集查询
///
///
///
///
public static SqlMapper.GridReader MultyQuery(string sql, object parms = null)
{
using (IDbConnection conn = CreateConnection())
{
return conn.QueryMultiple(sql, parms);
}
}
///
/// 单个数据集查询
///
///
///
///
public static TEntity FirstOrDefault
(string sql,Func {
using (IDbConnection conn = CreateConnection())
{
return conn.Query
(sql, parms).Where(selector).FirstOrDefault(); }
}
}
}
我把增删改查抽象出来了，少不了的就是SQL语句的生成，生成SQL语句，要么是映射，要么是反射，而我用的是反射，给一个Entity类，我读取他所有属性和字段，然后生成对应的SQL语句。 NetUtility.Dapper.Core.DataMapping.cs
using System; using System.Collections.Generic; using System.Configuration; using System.Linq; using System.Reflection; using System.Text; using System.Threading.Tasks; namespace NetUtility.Dapper.Core { internal class DataMapping where TModel : class { #region 数据库类型+DataBaseType /// /// 数据库类型 /// public static string DataBaseType { get { string strType = ConfigurationManager.AppSettings["DataBaseType"]; if (!string.IsNullOrEmpty(strType)) { return strType; } else { return string.Empty; } } } #endregion #region 主键属性字段+PrimaryKey /// /// 主键字段名称 /// public static string PrimaryKey { get { Type t = typeof(TModel); TableInfoAttribute tableInfo = t.GetCustomAttribute(typeof(TableInfoAttribute), true) as TableInfoAttribute; if (tableInfo!=null)//如果没有标识表信息特性，则通过表名向数据库中得到主键信息 { return tableInfo.PrimaryKey; } else { string tableName = TableName(); return DataBaseAccess.ExecuteScalar("SELECT name FROM SysColumns WHERE id=Object_Id('" + tableName + "') and colid=(select top 1 colid from sysindexkeys where id=Object_Id('" + tableName + "'))").ToString(); } } } #endregion #region 获取表名+TableName /// /// 获取表名 /// /// 数据库表名前缀 /// /// Select 查询语句 /// /// /// Insert 非Null属性的对象实例 Sql 语句 /// /// /// /// Delete Sql 语句 /// /// /// Update 非Null属性的对象实例 Sql语句 /// /// /// /// 非主键且非Null属性 /// /// /// list = new List(); string key = PrimaryKey; if (props != null && props.Length > 0) { foreach (PropertyInfo prop in props) { if (prop.GetValue(model, null) != null && !prop.Name.Equals(key, StringComparison.OrdinalIgnoreCase)) { list.Add(prop.Name); } } } return list.ToArray(); } #endregion } } 代码中的TableInfoAttribute 类是我建一个属性特性类，用于标识表名和主键名称的特性类，假如Entity实体类上面没有标识主键名称，框架默认会用Entity类名作为表名，建议***标识一下表名和主键名称。
NetUtility.Dapper.Core.TableInfoAttribute.cs
using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; namespace NetUtility.Dapper.Core { [AttributeUsage(AttributeTargets.Class | AttributeTargets.Property, AllowMultiple = true, Inherited = true)] /// /// 标识表名、主键等信息特性类 /// public class TableInfoAttribute : Attribute { /// /// 数据库表名 /// public string TableName { get; set; } /// /// 主键名称 /// public string PrimaryKey { get; set; } public TableInfoAttribute() { } public TableInfoAttribute(string tableName, string key) { this.TableName = tableName; this.PrimaryKey = key; } } }using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; namespace NetUtility.Dapper.Core { [AttributeUsage(AttributeTargets.Class | AttributeTargets.Property, AllowMultiple = true, Inherited = true)] /// /// 标识表名、主键等信息特性类 /// public class TableInfoAttribute : Attribute { /// /// 数据库表名 /// public string TableName { get; set; } /// /// 主键名称 /// public string PrimaryKey { get; set; } public TableInfoAttribute() { } public TableInfoAttribute(string tableName, string key) { this.TableName = tableName; this.PrimaryKey = key; } } }好，下面就是新建一个抽象类，用于抽象出增删改查的 ExecuteSql
NetUtility.Dapper.Core.ExecuteSql.cs
using Dapper; using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; namespace NetUtility.Dapper.Core { public abstract class ExecuteSql where TModel : class { #region Insert非Null属性的对象实例+Insert(TModel model) /// /// Insert非Null属性的对象实例 /// /// /// .GetInsertSql(model); object res = DataBaseAccess.ExecuteScalar(sql, model); if (res != null) { return Convert.ToInt32(res); } return 0; } #endregion #region Select * 查询+Query() /// /// Select * 查询 /// /// Query() { string sql = DataMapping.GetQuerySql(); return DataBaseAccess.Query(sql); } #endregion #region 带查询条件的Select查询+Query(Func selector) /// /// 带查询条件的Select查询 /// /// /// Query(Func selector) { string sql = DataMapping.GetQuerySql(); return DataBaseAccess.Query(sql, selector); } #endregion #region 得到一个对象的实例+FirstOrDefault(Func selector = null) /// /// 得到一个对象的实例 /// /// /// selector = null) { string sql = DataMapping.GetQuerySql(); return DataBaseAccess.FirstOrDefault(sql, selector); } #endregion #region 批量删除+Delete(string[] IdList) /// /// 批量删除 /// /// /// .GetDeleteSql(), new { IdList = IdList }); } #endregion #region Update 一个非Null属性的对象+Update(TModel model) /// /// Update 一个非Null属性的对象 /// /// /// .GetUpdateSql(model), model); } #endregion #region 获取多个数据集+MultyQuery(string sql, object param = null) /// /// 获取多个数据集 /// /// /// /// ExecuteSql.cs 类中的方法全是 virsual方法，使用者可以重写他，特别是查询方法，一定会被重写掉。现在NetUtility.Dapper.Core项目中的类全部写完了，现在 是我业务类的引用了，我现在只需要建一个业务类继承这个抽象类，这些增删改查方法全都有了，已经不需要写了！
下面是我的两个实体类，实体类用TableInfoAttribute特性类标识出了主键名称和表名称：
using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; using NetUtility.Dapper.Core; namespace NetUtility.Entity { [TableInfo(PrimaryKey ="Id",TableName ="Classes")] public class Classes { public int Id { get; set; } public string Name { get; set; } public string Code { get; set; } } } using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; using NetUtility.Dapper.Core; namespace NetUtility.Entity { [TableInfo(PrimaryKey = "Id", TableName = "Student")] public class Student { public int Id { get; set; } public string Name { get; set; } public string Code { get; set; } public int? Age { get; set; } public DateTime? JoinDate { get; set; } public int? ClassesId { get; set; } } }我再新建一个StudentRepertories业务类，继承ExecuteSql抽象类。
NetUtility.Repertories.StudentRepertories.cs
using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; using NetUtility.Dapper.Core; using NetUtility.Entity; using NetUtility.Entity.ExstendEntity;//这个是实体类的扩展类，项目中如不需要可移除 using System.Data; using Dapper; namespace NetUtility.Repertories { public class StudentRepertories : ExecuteSql { public override List Query() { return base.Query(); } public List QueryInfo() { string sql = "select * from Student a left join Classes b on a.ClassesId=b.Id"; using (IDbConnection conn = DataBaseAccess.CreateConnection()) { return conn.Query(sql, (stu, classes) => { stu.ClassesModel = classes; return stu; }).ToList(); } } } } 好了，现在我们只需要建一个控制台测试一下有没有问题就是了，亲测，木有问题。
NetUtility.ConsoleItem
using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; using NetUtility.Repertories; using NetUtility.Entity; namespace NetUtility.ConsoleItem { class Program { static void Main(string[] args) { //业务对象 StudentRepertories stu = new StudentRepertories(); //实体对象 var model = new Student(){Age = 100,ClassesId = 1,Code = "3200020021",JoinDate = DateTime.Now,Name = "老徐"}; //新增一个对象 int StudentId = stu.Insert(model); var newModel = stu.FirstOrDefault(a => a.Id == StudentId); //Lambda表达式查询 var list = stu.Query(a => a.Age == 100); //不带参数查询 var studentInfoList = stu.QueryInfo(); #region 更新 newModel.Code = "1111111111"; newModel.Id = StudentId; stu.Update(newModel); #endregion // 删除 stu.Delete(new string[] { newModel.Id.ToString() }); Console.ReadKey(); } } }到此，相信大家对"C#抽象增删改怎么实现"有了更深的了解，不妨来实际操作一番吧！这里是网站，更多相关内容可以进入相关频道进行查询，关注我们，继续学习！
