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Winform中連接Mysql8并查詢表中數據進行顯示：

Winform中連接Mysql8并查詢表中數據進行顯示_BADAO_LIUMANG_QIZHI的博客-CSDN博客

與上面實現的流程類似，怎么在連接mysql的基礎上實現執行查詢、編輯、刪除、插入操作的sql。

但是不能執行"drop", "drop database" , "drop table" , "truncate", "alter","rename" , "create"等這些dll語句。

同上面一樣，項目中引入Mysql.Data.dll依賴并設計窗體布局如下

注：

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實現

1、聲明變量獲取數據庫連接的相關參數

??????? 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、連接按鈕的點擊事件

??????? 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連接時，最后一句一定要加！！！mySqlConnection = new MySqlConnection(connetStr);try{mySqlConnection.Open(); //連接數據庫MessageBox.Show("數據庫連接成功", "提示", MessageBoxButtons.OK);}catch (MySqlException ex){MessageBox.Show(ex.Message, "提示", MessageBoxButtons.OK);???? //顯示錯誤信息}}

連接數據庫效果

2、執行新增、編輯、刪除的sql的按鈕的點擊事件

??????? 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("執行sql為空");???????????}else if (!badaoHelper.checkSql(searchStr)){MessageBox.Show("執行sql不被允許");}else if (mySqlConnection.State == ConnectionState.Closed) {MessageBox.Show("請先建立數據庫連接");}else {try {dbCmd = new MySqlCommand();dbCmd.CommandText = searchStr;dbCmd.Connection = mySqlConnection;int result = dbCmd.ExecuteNonQuery();if (result > 0){MessageBox.Show("sql執行成功，數據庫連接關閉，受影響的行數：" + result);mySqlConnection.Close();}else {MessageBox.Show("sql執行失敗，數據庫連接關閉，受影響的行數：" + result);mySqlConnection.Close();}}catch (Exception ex) {mySqlConnection.Close();MessageBox.Show("sql執行失敗，數據庫連接關閉，報錯信息:" + ex.Message);}}}

執行sql的效果

這其中用到了校驗是否包含指定sql的工具類方法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、執行查詢sql的執行按鈕的點擊事件

??????? private void button_sql_query_Click(object sender, EventArgs e){string searchStr = this.textBox_sql_query.Text.Trim();if (String.IsNullOrEmpty(searchStr)){MessageBox.Show("執行sql為空");} else if (!badaoHelper.checkSql(searchStr)) {MessageBox.Show("執行sql不被允許");}else if (mySqlConnection.State == ConnectionState.Closed){MessageBox.Show("請先建立數據庫連接");}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("報錯信息:" + ex.Message);}}}

執行查詢sql的效果

4、完整示例代碼

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連接時，最后一句一定要加！！！mySqlConnection = new MySqlConnection(connetStr);try{mySqlConnection.Open(); //連接數據庫MessageBox.Show("數據庫連接成功", "提示", MessageBoxButtons.OK);}catch (MySqlException ex){MessageBox.Show(ex.Message, "提示", MessageBoxButtons.OK);???? //顯示錯誤信息}}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("執行sql為空");???????????}else if (!badaoHelper.checkSql(searchStr)){MessageBox.Show("執行sql不被允許");}else if (mySqlConnection.State == ConnectionState.Closed) {MessageBox.Show("請先建立數據庫連接");}else {try {dbCmd = new MySqlCommand();dbCmd.CommandText = searchStr;dbCmd.Connection = mySqlConnection;int result = dbCmd.ExecuteNonQuery();if (result > 0){MessageBox.Show("sql執行成功，數據庫連接關閉，受影響的行數：" + result);mySqlConnection.Close();}else {MessageBox.Show("sql執行失敗，數據庫連接關閉，受影響的行數：" + result);mySqlConnection.Close();}}catch (Exception ex) {mySqlConnection.Close();MessageBox.Show("sql執行失敗，數據庫連接關閉，報錯信息:" + 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("執行sql為空");} else if (!badaoHelper.checkSql(searchStr)) {MessageBox.Show("執行sql不被允許");}else if (mySqlConnection.State == ConnectionState.Closed){MessageBox.Show("請先建立數據庫連接");}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("報錯信息:" + ex.Message);}}}} }

總結

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