c#操作~

一、连接access数据库

连接数据库:工具—连接到数据库

复制粘贴路径备用。

using System;using System.Collections.Generic;using System.Data;//操作数据表using System.Data.OleDb; //连接access excelusing System.Linq;using System.Text;using System.Threading.Tasks;namespace database{internal class Program{static void Main(string[] args){Access access = new Access();access.Find();Console.ReadKey();access.Add();Console.WriteLine("回车继续");Console.ReadKey();access.Del();Console.WriteLine("回车继续");Console.ReadKey();access.Change();Console.WriteLine("回车继续");Console.ReadKey();access.Get();}}//连接数据库class Access{OleDbConnection oleDb = new OleDbConnection(@"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=F:\vs\test.mdb"); //需要new一个人public Access() {oleDb.Open(); //利用oleDb中的组件open函数打开数据库}public void Get() //获取数据{string sql = "select * from student"; //从student里选取所有内容，*表示所有OleDbDataAdapter dbDataAdapter = new OleDbDataAdapter(sql, oleDb); //创建适配对象DataTable dt = new DataTable();//新建表对象dbDataAdapter.Fill(dt); //用适配对象填充表对象foreach(DataRow item in dt.Rows){Console.WriteLine(item[0] + "|" + item[1] + "|" + item[2] + "|" + item[3]);}}public void Find() //获取表中姓名是小明的内容{string sql = "select * from student WHERE 姓名='小明'";OleDbDataAdapter dbDataAdapter = new OleDbDataAdapter(sql, oleDb);DataTable dt = new DataTable();dbDataAdapter.Fill(dt);foreach (DataRow item in dt.Rows){Console.WriteLine(item[0] + "|" + item[1] + "|" + item[2] + "|" + item[3]);}}public bool Add() //往表中添加一条记录{string sql = "insert into student (姓名,年龄,学号) values ('小高','13','250')";OleDbCommand oleDbCommand = new OleDbCommand(sql, oleDb);int i = oleDbCommand.ExecuteNonQuery(); //返回被修改的数目return i > 0;}public bool Del() //删除姓名是小红的记录{string sql = "delete from student where 姓名='小红'";OleDbCommand oleDbCommand = new OleDbCommand(sql, oleDb);int i = oleDbCommand.ExecuteNonQuery();return i > 0;}public bool Change()//将表student中姓名为小东的学号号修改成222{string sql = "update student set 学号='222' where 姓名='小东'";OleDbCommand oleDbCommand = new OleDbCommand(sql, oleDb);int i = oleDbCommand.ExecuteNonQuery();return i > 0;}}}Provider=Microsoft.ACE.OLEDB.12.0;Data Source=F:\vs\test.mdb

常见问题

1.未经处理的异常System.InvalidOperationException:“The ‘Microsoft.ACE.OLEDB.12.0’ provider is not registered on the local machine.”

项目名称→右键“属性”→生成→目标平台→将“Any CPU”改为“x64”

2.错误CS1069未能在命名空间“System.Data.OleDb”中找到类型名“OleDbConnection”。

项目——管理Nuget程序包——搜索下载

二、DataTable操作

三、C#其他小操作

注释/// ＜summary＞

public class TestTwo : MonoBehaviour{/// 
/// This is Function 1/// 
public static void Function1(){}// This is Function 2public static void Function2(){}}

鼠标放在调用的Function1和Function2函数时，Function1直接显示了注释说明，Function2则什么也没有，需按F12进入函数查看注释。若需要两行注释，如下

 /// 
/// This is Function1.1/// This is Function1.2/// 
public static void Function1() { }