时间:2021-07-01 10:21:17 帮助过:13人阅读
这样我们就可以使用MySql.Data中的方法来连接数据库了,连接数据库代码如下:
- <span style="color: #000000;">
- String connetStr </span>= <span style="color: #800000;">"</span><span style="color: #800000;">server=127.0.0.1;port=3306;user=root;password=123; database=vs;</span><span style="color: #800000;">"</span><span style="color: #000000;">;
- </span><span style="color: #008000;">//usr:用户名,password:数据库密码,database:数据库名</span>
- MySqlConnection conn = <span style="color: #0000ff;">new</span><span style="color: #000000;"> MySqlConnection(connetStr);
- </span><span style="color: #0000ff;">try</span><span style="color: #000000;">
- {
- conn.Open();</span><span style="color: #008000;">//</span><span style="color: #008000;">打开通道,建立连接,可能出现异常,使用try catch语句</span>
- Console.WriteLine(<span style="color: #800000;">"</span><span style="color: #800000;">已经建立连接</span><span style="color: #800000;">"</span><span style="color: #000000;">);
- </span><span style="color: #000000;">
- }
- </span><span style="color: #0000ff;">catch</span><span style="color: #000000;"> (MySqlException ex)
- {
- Console.WriteLine(ex.Message);
- }
- </span><span style="color: #0000ff;">finally</span><span style="color: #000000;">
- {
- conn.Close();
- }</span>
如果连接数据库成功,我们就可以进行下面的操作了,取出数据并通过DataGridView展示出来了,代码如下:
- <span style="color: #000000;">
- String connetStr </span>= <span style="color: #800000;">"</span><span style="color: #800000;">server=127.0.0.1;port=3306;user=root;password=123; database=vs;</span><span style="color: #800000;">"</span><span style="color: #000000;">;
- </span>
- MySqlConnection conn = <span style="color: #0000ff;">new</span><span style="color: #000000;"> MySqlConnection(connetStr);
- </span><span style="color: #0000ff;">try</span><span style="color: #000000;">
- {
- conn.Open();</span><span style="color: #008000;">//</span><span style="color: #008000;">打开通道,建立连接,可能出现异常,使用try catch语句</span>
- Console.WriteLine(<span style="color: #800000;">"</span><span style="color: #800000;">已经建立连接</span><span style="color: #800000;">"</span><span style="color: #000000;">);<br></span>
- <span style="color: #0000ff;">string</span> sql = <span style="color: #800000;">"</span><span style="color: #800000;">select * from salecar</span><span style="color: #800000;">"</span><span style="color: #000000;">;
- MySqlCommand cmd </span>= <span style="color: #0000ff;">new</span><span style="color: #000000;"> MySqlCommand(sql, conn);
- MySqlDataReader reader </span>= cmd.ExecuteReader();<span style="color: #008000;">//</span><span style="color: #008000;">执行ExecuteReader()返回一个MySqlDataReader对象</span>
- <span style="color: #0000ff;">while</span> (reader.Read())
- <span style="color: #000000;"> {
- </span><span style="color: #0000ff;">int</span> index = <span style="color: #0000ff;">this</span><span style="color: #000000;">.dataGridView1.Rows.Add();
- </span><span style="color: #0000ff;">this</span>.dataGridView1.Rows[index].Cells[<span style="color: #800080;">0</span>].Value = reader.GetString(<span style="color: #800000;">"</span><span style="color: #800000;">name</span><span style="color: #800000;">"</span><span style="color: #000000;">);
- </span><span style="color: #0000ff;">this</span>.dataGridView1.Rows[index].Cells[<span style="color: #800080;">1</span>].Value = reader.GetString(<span style="color: #800000;">"</span><span style="color: #800000;">describe</span><span style="color: #800000;">"</span><span style="color: #000000;">);
- </span><span style="color: #0000ff;">this</span>.dataGridView1.Rows[index].Cells[<span style="color: #800080;">2</span>].Value = reader.GetString(<span style="color: #800000;">"</span><span style="color: #800000;">price</span><span style="color: #800000;">"</span><span style="color: #000000;">);
- </span><span style="color: #0000ff;">this</span>.dataGridView1.Rows[index].Cells[<span style="color: #800080;">3</span>].Value = reader.GetInt32(<span style="color: #800000;">"</span><span style="color: #800000;">salenumber</span><span style="color: #800000;">"</span><span style="color: #000000;">);
- }
- }
- </span><span style="color: #0000ff;">catch</span><span style="color: #000000;"> (MySqlException ex)
- {
- Console.WriteLine(ex.Message);
- }
- </span><span style="color: #0000ff;">finally</span><span style="color: #000000;">
- {
- conn.Close();
- }</span>
这样我们就完成了C#窗体连接MySql并通过DataGridView展示数据,下面是效果图和全部代码:
全部代码:
- <span style="color: #0000ff;">using</span><span style="color: #000000;"> System;
- </span><span style="color: #0000ff;">using</span><span style="color: #000000;"> System.Collections.Generic;
- </span><span style="color: #0000ff;">using</span><span style="color: #000000;"> System.ComponentModel;
- </span><span style="color: #0000ff;">using</span><span style="color: #000000;"> System.Data;
- </span><span style="color: #0000ff;">using</span><span style="color: #000000;"> System.Drawing;
- </span><span style="color: #0000ff;">using</span><span style="color: #000000;"> System.Linq;
- </span><span style="color: #0000ff;">using</span><span style="color: #000000;"> System.Text;
- </span><span style="color: #0000ff;">using</span><span style="color: #000000;"> System.Threading.Tasks;
- </span><span style="color: #0000ff;">using</span><span style="color: #000000;"> System.Windows.Forms;
- </span><span style="color: #0000ff;">using</span><span style="color: #000000;"> MySql.Data.MySqlClient;
- </span><span style="color: #0000ff;">namespace</span><span style="color: #000000;"> WindowsFormsApp1
- {
- </span><span style="color: #0000ff;">public</span> <span style="color: #0000ff;">partial</span> <span style="color: #0000ff;">class</span><span style="color: #000000;"> Form3 : Form
- {
- </span><span style="color: #0000ff;">public</span><span style="color: #000000;"> Form3()
- {
- InitializeComponent();
- a();
- }
- </span><span style="color: #0000ff;">private</span> <span style="color: #0000ff;">void</span> button1_Click(<span style="color: #0000ff;">object</span><span style="color: #000000;"> sender, EventArgs e)
- {
- Form1 fm1 </span>= <span style="color: #0000ff;">new</span><span style="color: #000000;"> Form1();
- </span><span style="color: #0000ff;">this</span><span style="color: #000000;">.Hide();
- fm1.ShowDialog();
- Application.ExitThread();
- }
- </span><span style="color: #0000ff;">private</span> <span style="color: #0000ff;">void</span> dataGridView1_CellContentClick(<span style="color: #0000ff;">object</span><span style="color: #000000;"> sender, DataGridViewCellEventArgs e)
- {
- }
- </span><span style="color: #0000ff;">public</span> <span style="color: #0000ff;">void</span><span style="color: #000000;"> a()
- {
- String connetStr </span>= <span style="color: #800000;">"</span><span style="color: #800000;">server=127.0.0.1;port=3306;user=root;password=123; database=vs;</span><span style="color: #800000;">"</span><span style="color: #000000;">;</span>
- MySqlConnection conn = <span style="color: #0000ff;">new</span><span style="color: #000000;"> MySqlConnection(connetStr);
- </span><span style="color: #0000ff;">try</span><span style="color: #000000;">
- {
- conn.Open();</span><span style="color: #008000;">//</span><span style="color: #008000;">打开通道,建立连接,可能出现异常,使用try catch语句</span>
- Console.WriteLine(<span style="color: #800000;">"</span><span style="color: #800000;">已经建立连接</span><span style="color: #800000;">"</span><span style="color: #000000;">);
- </span><span style="color: #008000;">//</span><span style="color: #008000;">在这里使用代码对数据库进行增删查改</span>
- <span style="color: #0000ff;">string</span> sql = <span style="color: #800000;">"</span><span style="color: #800000;">select * from salecar</span><span style="color: #800000;">"</span><span style="color: #000000;">;
- MySqlCommand cmd </span>= <span style="color: #0000ff;">new</span><span style="color: #000000;"> MySqlCommand(sql, conn);
- MySqlDataReader reader </span>= cmd.ExecuteReader();<span style="color: #008000;">//</span><span style="color: #008000;">执行ExecuteReader()返回一个MySqlDataReader对象</span>
- <span style="color: #0000ff;">while</span> (reader.Read())
- <span style="color: #000000;"> {
- </span><span style="color: #0000ff;">int</span> index = <span style="color: #0000ff;">this</span><span style="color: #000000;">.dataGridView1.Rows.Add();
- </span><span style="color: #0000ff;">this</span>.dataGridView1.Rows[index].Cells[<span style="color: #800080;">0</span>].Value = reader.GetString(<span style="color: #800000;">"</span><span style="color: #800000;">name</span><span style="color: #800000;">"</span><span style="color: #000000;">);
- </span><span style="color: #0000ff;">this</span>.dataGridView1.Rows[index].Cells[<span style="color: #800080;">1</span>].Value = reader.GetString(<span style="color: #800000;">"</span><span style="color: #800000;">describe</span><span style="color: #800000;">"</span><span style="color: #000000;">);
- </span><span style="color: #0000ff;">this</span>.dataGridView1.Rows[index].Cells[<span style="color: #800080;">2</span>].Value = reader.GetString(<span style="color: #800000;">"</span><span style="color: #800000;">price</span><span style="color: #800000;">"</span><span style="color: #000000;">);
- </span><span style="color: #0000ff;">this</span>.dataGridView1.Rows[index].Cells[<span style="color: #800080;">3</span>].Value = reader.GetInt32(<span style="color: #800000;">"</span><span style="color: #800000;">salenumber</span><span style="color: #800000;">"</span><span style="color: #000000;">);
- }
- }
- </span><span style="color: #0000ff;">catch</span><span style="color: #000000;"> (MySqlException ex)
- {
- Console.WriteLine(ex.Message);
- }
- </span><span style="color: #0000ff;">finally</span><span style="color: #000000;">
- {
- conn.Close();
- }
- }
- }
- }</span>
效果:
数据库表:
C#窗体连接MySql并通过DataGridView展示数据
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