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Winform中连接Mysql8并查询表中数据进行显示：
Winform中连接Mysql8并查询表中数据进行显示_BADAO_LIUMANG_QIZHI的博客-CSDN博客
与上面实现的流程类似，怎么在连接mysql的基础上实现执行查询、编辑、删除、插入操作的sql。
但是不能执行”drop”, “drop database” , “drop table” , “truncate”, “alter”,”rename” , “create”等这些dll语句。
同上面一样，项目中引入Mysql.Data.dll依赖并设计窗体布局如下
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实现
1、声明变量获取数据库连接的相关参数
string connetStr = String.Empty;
MySqlConnection mySqlConnection = null;
String hostaddress = String.Empty;
String port = String.Empty;
String databaseName = String.Empty;
String name = String.Empty;
String pass = String.Empty;
private MySqlCommand dbCmd = null;
private MySqlDataReader dbDataReader = null;2、连接按钮的点击事件
private void button_connect_Click(object sender, EventArgs e)
{
hostaddress = this.textBox_host.Text.Trim();
databaseName = this.textBox_database.Text.Trim();
name = this.textBox_username.Text.Trim();
pass = this.textBox_password.Text.Trim();
port = this.textBox_port.Text.Trim();
connetStr = "server=" + hostaddress + ";port="+ port+";User Id=" + name + ";password=" + pass + ";database=" + databaseName; //localhost不支持ssl连接时，最后一句一定要加！！！
mySqlConnection = new MySqlConnection(connetStr);
try
{
mySqlConnection.Open(); //连接数据库
MessageBox.Show("数据库连接成功", "提示", MessageBoxButtons.OK);
}
catch (MySqlException ex)
{
MessageBox.Show(ex.Message, "提示", MessageBoxButtons.OK); //显示错误信息
}
}连接数据库效果
2、执行新增、编辑、删除的sql的按钮的点击事件
private void button_executeSql_Click(object sender, EventArgs e)
{
string searchStr = this.textBox_sql.Text.Trim();
if (String.IsNullOrEmpty(this.textBox_sql.Text))
{
MessageBox.Show("执行sql为空");
}
else if (!badaoHelper.checkSql(searchStr))
{
MessageBox.Show("执行sql不被允许");
}
else if (mySqlConnection.State == ConnectionState.Closed) {
MessageBox.Show("请先建立数据库连接");
}
else {
try {
dbCmd = new MySqlCommand();
dbCmd.CommandText = searchStr;
dbCmd.Connection = mySqlConnection;
int result = dbCmd.ExecuteNonQuery();
if (result > 0)
{
MessageBox.Show("sql执行成功，数据库连接关闭，受影响的行数：" + result);
mySqlConnection.Close();
}
else {
MessageBox.Show("sql执行失败，数据库连接关闭，受影响的行数：" + result);
mySqlConnection.Close();
}
}
catch (Exception ex) {
mySqlConnection.Close();
MessageBox.Show("sql执行失败，数据库连接关闭，报错信息:" + ex.Message);
}
}
}执行sql的效果
这其中用到了校验是否包含指定sql的工具类方法checkSql
public static bool checkSql(string sql)
{
bool isRight = true;
string[] notAllowKeyWords = { "drop", "drop database" , "drop table" , "truncate", "alter","rename" , "create" };
for (int i = 0; i < notAllowKeyWords.Length; i++)
{
string arr = notAllowKeyWords[i];
if (sql.ToLower().Contains(arr.ToLower())) {
isRight = false;
}
}
return isRight;
}3、执行查询sql的执行按钮的点击事件
private void button_sql_query_Click(object sender, EventArgs e)
{
string searchStr = this.textBox_sql_query.Text.Trim();
if (String.IsNullOrEmpty(searchStr))
{
MessageBox.Show("执行sql为空");
} else if (!badaoHelper.checkSql(searchStr)) {
MessageBox.Show("执行sql不被允许");
}
else if (mySqlConnection.State == ConnectionState.Closed)
{
MessageBox.Show("请先建立数据库连接");
}
else
{
try
{
MySqlDataAdapter adapter = new MySqlDataAdapter(searchStr, mySqlConnection);
DataSet dataSet = new DataSet();
adapter.Fill(dataSet, "table1");
this.dataGridView_select.DataSource = dataSet.Tables["table1"];
}
catch (Exception ex)
{
MessageBox.Show("报错信息:" + ex.Message);
}
}
}执行查询sql的效果
4、完整示例代码
using MySql.Data.MySqlClient;
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;
namespace BdtdDataUpload
{
public partial class Main : Form
{
string connetStr = String.Empty;
MySqlConnection mySqlConnection = null;
String hostaddress = String.Empty;
String port = String.Empty;
String databaseName = String.Empty;
String name = String.Empty;
String pass = String.Empty;
private MySqlCommand dbCmd = null;
private MySqlDataReader dbDataReader = null;
public Main()
{
InitializeComponent();
}
private void button_connect_Click(object sender, EventArgs e)
{
hostaddress = this.textBox_host.Text.Trim();
databaseName = this.textBox_database.Text.Trim();
name = this.textBox_username.Text.Trim();
pass = this.textBox_password.Text.Trim();
port = this.textBox_port.Text.Trim();
connetStr = "server=" + hostaddress + ";port="+ port+";User Id=" + name + ";password=" + pass + ";database=" + databaseName; //localhost不支持ssl连接时，最后一句一定要加！！！
mySqlConnection = new MySqlConnection(connetStr);
try
{
mySqlConnection.Open(); //连接数据库
MessageBox.Show("数据库连接成功", "提示", MessageBoxButtons.OK);
}
catch (MySqlException ex)
{
MessageBox.Show(ex.Message, "提示", MessageBoxButtons.OK); //显示错误信息
}
}
private void button_disconnect_Click(object sender, EventArgs e)
{
if (mySqlConnection.State == ConnectionState.Open) {
mySqlConnection.Close();
}
}
private void button_executeSql_Click(object sender, EventArgs e)
{
string searchStr = this.textBox_sql.Text.Trim();
if (String.IsNullOrEmpty(this.textBox_sql.Text))
{
MessageBox.Show("执行sql为空");
}
else if (!badaoHelper.checkSql(searchStr))
{
MessageBox.Show("执行sql不被允许");
}
else if (mySqlConnection.State == ConnectionState.Closed) {
MessageBox.Show("请先建立数据库连接");
}
else {
try {
dbCmd = new MySqlCommand();
dbCmd.CommandText = searchStr;
dbCmd.Connection = mySqlConnection;
int result = dbCmd.ExecuteNonQuery();
if (result > 0)
{
MessageBox.Show("sql执行成功，数据库连接关闭，受影响的行数：" + result);
mySqlConnection.Close();
}
else {
MessageBox.Show("sql执行失败，数据库连接关闭，受影响的行数：" + result);
mySqlConnection.Close();
}
}
catch (Exception ex) {
mySqlConnection.Close();
MessageBox.Show("sql执行失败，数据库连接关闭，报错信息:" + ex.Message);
}
}
}
private void button_sql_query_Click(object sender, EventArgs e)
{
string searchStr = this.textBox_sql_query.Text.Trim();
if (String.IsNullOrEmpty(searchStr))
{
MessageBox.Show("执行sql为空");
} else if (!badaoHelper.checkSql(searchStr)) {
MessageBox.Show("执行sql不被允许");
}
else if (mySqlConnection.State == ConnectionState.Closed)
{
MessageBox.Show("请先建立数据库连接");
}
else
{
try
{
MySqlDataAdapter adapter = new MySqlDataAdapter(searchStr, mySqlConnection);
DataSet dataSet = new DataSet();
adapter.Fill(dataSet, "table1");
this.dataGridView_select.DataSource = dataSet.Tables["table1"];
}
catch (Exception ex)
{
MessageBox.Show("报错信息:" + ex.Message);
}
}
}
}
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