第3章 数据库操作-通过DataGridView控件进行数据库的操作
通过DataGridView控件进行数据库的操作
using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Threading.Tasks; using System.Windows.Forms; using System.Data.OleDb; using System.IO; using System.Security.Cryptography; namespace WindowsFormsApp1 { public partial class Form1 : Form { public Form1() { InitializeComponent(); } private string sql = "select * from 表1"; private string connectionName = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source="+ Directory.GetCurrentDirectory()+ "\\Database.mdb;"; private void button1_Click(object sender, EventArgs e) { OleDbConnection conn = new OleDbConnection(connectionName); conn.Open(); OleDbCommand cmd = new OleDbCommand(sql,conn); OleDbDataAdapter apt = new OleDbDataAdapter(cmd); DataTable table = new DataTable(); apt.Fill(table); dataGridView1.DataSource = table; apt.Dispose(); //查询数据到textBox1 string sql2 = "select 体重 from 表1"; cmd=new OleDbCommand(sql2, conn); OleDbDataReader oleDbDataReader = cmd.ExecuteReader(); //每次读一行数据 oleDbDataReader.Read(); oleDbDataReader.Read(); textBox1.Text = oleDbDataReader[0].ToString(); oleDbDataReader.Close(); conn.Close(); //update数据 string sql3 = "update 表1 set 姓名='王五' where 年龄=20"; OleDbConnection conn2 = new OleDbConnection(connectionName); conn2.Open(); cmd = new OleDbCommand(sql3, conn2); cmd.ExecuteNonQuery(); conn.Close(); } } }