ORM反射

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Data.SqlClient;
using Dapper;
using System.Reflection;

namespace DemoOrmHelper
{
public class OrmHelper<T> where T : class, new()
{
//连接数据库
SqlConnection conn = new SqlConnection("Data Source=DESKTOP-O7U2DEC;Initial Catalog=B2C;Integrated Security=True");
/// <summary>
/// 使用反射，添加的Sql语句
/// </summary>
/// <param name="model"></param>
/// <returns></returns>
public int ExecuteNonQuary(T model)
{
//获取类型，字段不知道
Type type = model.GetType();
//实例化字符串
StringBuilder stringBuilder = new StringBuilder();
//拼接Sql语句，固定的
stringBuilder.Append($"insert into {type.Name} values (");
//获取字段属性的名称
PropertyInfo[] properties = type.GetProperties();
//循环拼接
foreach (PropertyInfo item in properties)
{
if(item.Name != "ID")
{
stringBuilder.Append($"'{item.GetValue(model)}',");
}
}
//去掉最后一个逗号
string sql = $"{stringBuilder.ToString().TrimEnd(',')})";
int code = conn.Execute(sql);
return code;
}
/// <summary>
/// 显示
/// </summary>
/// <returns></returns>
public List<T> GetList()
{
//获取类型
Type type = typeof(T);
//Sql语句
string sql = $"select * from {type.Name}";
return conn.Query<T>(sql).ToList();
}
/// <summary>
/// 删除
/// </summary>
/// <param name="ID"></param>
/// <returns></returns>
public int Delete(int ID)
{
//获取类型
Type type = typeof(T);
string sql = $"delete from {type.Name} where ID={ID}";
int code = conn.Execute(sql);
return code;
}
/// <summary>
/// 修改
/// </summary>
/// <param name="model"></param>
/// <returns></returns>
public int Update(T model)
{
//获取类型
Type type = model.GetType();
StringBuilder stringBuilder = new StringBuilder();
//拼接Sql语句，固定的
stringBuilder.Append($"update {type.Name} set ");
//获取字段属性的名称
PropertyInfo[] properties = type.GetProperties();
//定义ID，修改的条件
object id = null;
foreach (PropertyInfo item in properties)
{
if(item.Name != "ID")
{
stringBuilder.Append($"{item.Name}='{item.GetValue(model)}',");
}
else
{
id = item.GetValue(model);
}
}
//去掉最后一个逗号
string sql = $"{stringBuilder.ToString().TrimEnd(',')} where ID={id}";
int code = conn.Execute(sql);
return code;
}
}
}