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折騰了好久，蒙圈了很久，終于調(diào)用數(shù)據(jù)庫成功，小白一個，把學(xué)習(xí)經(jīng)驗分享一下，，希望高手指點。。。

首先你要有C#基礎(chǔ)吧，http://www.runoob.com/csharp/csharp-operators.html；其次你要知道數(shù)據(jù)庫是干嘛用的，可以百度搜；

安裝VS2017；這個是C#開發(fā)環(huán)境，也可以弄數(shù)據(jù)庫；
  

然后就新建一個C#桌面應(yīng)用，畫一個按鈕  

數(shù)據(jù)庫怎么弄呢，https://jingyan.baidu.com/album/9f63fb91893ac3c8410f0e58.html?picindex=1；

窗體應(yīng)用怎么連接數(shù)據(jù)庫呢  https://www.cnblogs.com/makqiq/p/5882351.html
下圖是我設(shè)置的表，以及窗體查詢數(shù)據(jù)庫里的數(shù)據(jù)  
  
點擊運行


  
下面附上程序
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Data.SqlClient;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;


namespace WindowsFormsApp4
{
    public partial class Form1 : Form //窗體1
    {
        private string connectString = @"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=C:\Users\123\Documents\mydata.mdf;Integrated Security=True;Connect Timeout=30";//這個是連接數(shù)據(jù)庫的字符串，右擊你建立的數(shù)據(jù)庫，屬性，連接字符串復(fù)制過來，記得加上@哦

        public Form1()
        {
            InitializeComponent();//初始化
        }

        private void Form1_Load(object sender, EventArgs e)
        {
        }

        private void button1_Click(object sender, EventArgs e)    //按鈕點擊事件
        {
            SqlConnection sqlCnt = new SqlConnection(connectString);//實例化sqlConnection
            sqlCnt.Open();   //打開數(shù)據(jù)庫
            MessageBox.Show("數(shù)據(jù)庫已打開");//打印數(shù)據(jù)庫
            SqlCommand command = sqlCnt .CreateCommand();//實例化SqlCommand
          
          
            command.CommandType = CommandType.Text;    //這個是執(zhí)行SQL語句
            command.CommandText = "SELECT*FROM dbo.[Table]"; //查詢你建立的表格
            SqlDataReader reader = command.ExecuteReader();     //執(zhí)行SQL，返回一個“流”
            while (reader.Read())
            {
                MessageBox.Show(Convert.ToString ( reader["id"])+ Convert.ToString(reader["姓名"]) + Convert.ToString(reader["年齡"]));  // 打印出每個用戶的信息
            }



            sqlCnt.Close();//關(guān)閉數(shù)據(jù)庫
            
          
        }
    }
}