Winform中使用Mysql.Data.dll实现连接Mysql数据库并执行sql语句(排除ddl等非法语句的执行)

场景

Winform中连接Mysql8并查询表中数据进行显示：

https://blog.csdn.net/BADAO_LIUMANG_QIZHI/article/details/120395988

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

注：

博客：
https://blog.csdn.net/badao_liumang_qizhi
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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);
                }

            }
        }
    }
}

posted on 2022-01-25 14:36 霸道流氓阅读(901) 评论(0) 编辑收藏举报

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