本来数据库准备用sqlite的。条件有限，就用Access了
using System;
using System.Collections.Generic;
using System.Linq;
using System.IO;
using System.Text;
using System.Data;
using System.Data.OleDb;
using System.Windows.Forms;
using System.Data.SqlClient;namespace XXXX.Util
{class AccessHelper{private static AccessHelper accHelper = null;private AccessHelper() { }private static string connStr = string.Format("Provider=Microsoft.ACE.OLEDB.12.0;Data Source={0}\\Database\\AccessDatabase.accdb;Persist Security Info=False;Jet OLEDB:Database Password=huahua.2020",Application.StartupPath);public static AccessHelper Instance(){if (accHelper == null){accHelper = new AccessHelper();}return accHelper;}/// <summary>/// 执行增加、删除、修改指令/// </summary>/// <param name="sql">增加、删除、修改的sql语句</param>/// <param name="param">sql语句的参数</param>/// <returns></returns>public int ExecuteNonQuery(string sql, params OleDbParameter[] param){try{using (OleDbConnection conn = new OleDbConnection(connStr)){using (OleDbCommand cmd = new OleDbCommand(sql, conn)){if (param != null){cmd.Parameters.AddRange(param);}conn.Open();return (cmd.ExecuteNonQuery());}}}catch (Exception ex){Console.WriteLine(ex.Message);return 0;}}/// <summary>/// 执行增加、删除、修改指令/// </summary>/// <param name="sql">增加、删除、修改的sql语句</param>/// <returns></returns>public int ExecuteNonQuery(string sql){try{using (OleDbConnection conn = new OleDbConnection(connStr)){using (OleDbCommand cmd = new OleDbCommand(sql, conn)){conn.Open();return (cmd.ExecuteNonQuery());}}}catch (Exception ex){Console.WriteLine(ex.Message);return 0;}}/// <summary>/// 执行查询指令，获取返回datatable/// </summary>/// <param name="sql">查询sql语句</param>/// <param name="param">sql语句的参数</param>/// <returns></returns>public DataTable ExecuteDatable(string sql, params OleDbParameter[] param){try{using (OleDbConnection conn = new OleDbConnection(connStr)){using (OleDbCommand cmd = new OleDbCommand(sql, conn)){if (param != null){cmd.Parameters.AddRange(param);}DataTable dt = new DataTable();OleDbDataAdapter sda = new OleDbDataAdapter(cmd);sda.Fill(dt);return (dt);}}}catch (Exception ex){Console.WriteLine(ex.Message);return null;}}/// <summary>/// 执行查询指令，获取返回datatable/// </summary>/// <param name="sql">查询sql语句</param>/// <param name="param">sql语句的参数</param>/// <returns></returns>public DataTable ExecuteDatable(string sql){try{using (OleDbConnection conn = new OleDbConnection(connStr)){using (OleDbCommand cmd = new OleDbCommand(sql, conn)){DataTable dt = new DataTable();OleDbDataAdapter sda = new OleDbDataAdapter(cmd);sda.Fill(dt);return dt;}}}catch (Exception ex){Console.WriteLine(ex.Message);return null;}}/// <summary>/// 将DataTable转为实体对象/// </summary>/// <typeparam name="T"> 目标类型 </typeparam>/// <param name="sourceDT">原DT</param>/// <returns>转换后的实体列表</returns>public List<T> GetEntityFromDataTable<T>(DataTable sourceDT) where T : class //数据库列名与属性保持一致{List<T> list = new List<T>(); // 获取需要转换的目标类型 Type type = typeof(T);try{foreach (DataRow dRow in sourceDT.Rows){// 实体化目标类型对象 object obj = Activator.CreateInstance(type);foreach (var prop in type.GetProperties()){if (prop.Name != "sTime"){// 给目标类型对象的各个属性值赋值 prop.SetValue(obj, dRow[prop.Name], null);}}list.Add(obj as T);}}catch (Exception ex){Console.WriteLine(ex.Message);}return list;}}}