如何让数据库在C＃

Question

这里是我的代码：

private void btnSimpan_Click(object sender, EventArgs e) 
    { 
     Employees employees = new Employees(); 
     employees.EmployeeNumber = txtEmployeeNumber.Text; 
     employees.LastName = txtLastName.Text; 
     employees.FirstName = txtFirstName.Text; 
     employees.Extension = txtExtension.Text; 
     employees.Email = txtEmail.Text; 
     employees.OfficeCode = cboOfficeCode.Text; 

     if (employees.OfficeCode.CompareTo("1") == 0 || employees.OfficeCode.CompareTo("2") == 0 || employees.OfficeCode.CompareTo("3") == 0) employees.ReportsTo = "1143"; 
     else if (employees.OfficeCode.CompareTo("4") == 0 || employees.OfficeCode.CompareTo("5") == 0) employees.ReportsTo = "1102"; 
     else employees.ReportsTo = "1088"; 

     employees.JobTitle = "Sales Rep"; 

     try 
     { 
      stringBuilder = new StringBuilder(); 
      stringBuilder.Append(@"INSERT INTO employees (employeeNumber, lastName, firstName, extension, email, officeCode, reportsTo, jobTitle) VALUES ("); 
      stringBuilder.Append(employees.EmployeeNumber); 
      stringBuilder.Append(", '"); 
      stringBuilder.Append(employees.LastName); 
      stringBuilder.Append("', '"); 
      stringBuilder.Append(employees.FirstName); 
      stringBuilder.Append("', '"); 
      stringBuilder.Append(employees.Extension); 
      stringBuilder.Append("', '"); 
      stringBuilder.Append(employees.Email); 
      stringBuilder.Append("', "); 
      stringBuilder.Append(employees.OfficeCode); 
      stringBuilder.Append(", '"); 
      stringBuilder.Append(employees.ReportsTo); 
      stringBuilder.Append("', '"); 
      stringBuilder.Append(employees.JobTitle); 
      stringBuilder.Append("')"); 

      comm = new MySqlCommand(); 
      comm.Connection = conn; 
      comm.CommandText = stringBuilder.ToString(); 

      // Memakai ExecuteNonQuery, return n data yang terkena dampak 
      int jmlDataTertambah = comm.ExecuteNonQuery(); 
      MessageBox.Show(jmlDataTertambah.ToString() + " data berhasil disimpan"); 
     } 
     catch (Exception ex) 
     { 
      MessageBox.Show(ex.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error); 
     } 
     finally 
     { 
      this.Close(); 
     } 
    } 

Answer 1

public partial class frmMain : Form 
{ 
    MySqlConnection conn = null; 

    public frmMain() 
    { 
     InitializeComponent(); 
    } 

    private void mnuConnect_Click(object sender, EventArgs e) 
    { 
     if (mnuConnect.Text.CompareTo("Connect") == 0) 
     { 
      String connString = @"Server=127.0.0.1;Database=product_sales_company;Uid=root;Pwd=;"; 

      try 
      { 
       conn = new MySqlConnection(connString); 
       conn.Open(); // Membuka koneksi 

       mnuEmployee.Enabled = true; 
       mnuConnect.Text = "Disconnect"; 
       lblStatusKoneksi.Text = "Connected"; 
      } 
      catch (Exception ex) 
      { 
       MessageBox.Show(ex.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Warning); 
      } 
     } 
     else 
     { 
      if (conn != null) 
      { 
       conn.Close(); // Menutup koneksi 
       conn.Dispose(); 
      } 

      foreach (Form form in this.MdiChildren) 
      { 
       form.Close(); 
      } 

      mnuEmployee.Enabled = false; 
      mnuConnect.Text = "Connect"; 
      lblStatusKoneksi.Text = "Disconnected"; 
     } 
    } 

    private void mnuExit_Click(object sender, EventArgs e) 
    { 
     if (conn != null) 
     { 
      conn.Close(); // Menutup koneksi 
      conn.Dispose(); 
     } 
     Application.Exit(); 
    } 

    private void mnuList_Click(object sender, EventArgs e) 
    { 
     // Cek apakah form yang memiliki jenis form yang sama (frmDaftarEmployee) sudah ada yang terbuka 
     foreach (Form form in this.MdiChildren) 
     { 
      if (form.GetType() == typeof(frmDaftarEmployee)) 
      { 
       form.Activate(); // Membuat form yang ditunjuk menjadi aktif 
       return; 
      } 
     } 

     frmDaftarEmployee formDafarEmployee = new frmDaftarEmployee(conn); 
     formDafarEmployee.MdiParent = this; 
     formDafarEmployee.Show(); 
    } 
} 
} 

Answer 2

要创建一个数据库，这样使用Create命令：

public void CreateDatabase(String createDb) 
     { 
      String connstr = ConfigurationManager.ConnectionStrings["Connstr"].ToString(); 
      MySqlConnection cnn = new MySqlConnection(connstr); 

      try 
      { 
       cnn.Open(); 
       object result = string.Empty; 
       MySqlCommand Command = new MySqlCommand(); 
       Command = cnn.CreateCommand(); 
       Command.CommandType = CommandType.Text; 
       Command.CommandText = createDb; 
       Command = new MySqlCommand(Query, cnn); 
       //result = (object)NpgCommand.ExecuteScalar(); 
       Command.ExecuteNonQuery(); 



      } 
      catch (Exception er) 
      { 
       String errorhere = er.Message; 
       if (cnn != null) 
       { 
        cnn.Close(); 
       } 


      } 
      finally 
      { 
       if (cnn != null) 
       { 
        cnn.Close(); 
       } 
      } 

     } 

然后调用您的Form_Load功能：

String createDb = "Create Database DBSample"; 
CreateDatabase(String createDb); 

确保你在你的app.config文件中设置了连接字符串。

它看起来像这样：

<configuration> 
    <connectionStrings> 
    <add name="Connstr" connectionString="data source=localhost;initial catalog=dbname;user=usename;password=password; default command timeout=120" /> 


     </connectionStrings> 
    </configuration> 

好运