我有一个 JComboBox，它从数据库检索数据并将其显示在 JTable 中。除了来自不同数据库的数据合并在 JTable 中之外，一切都运行良好。您知道如何仅显示特定数据库的数据吗？谢谢!
下面是我使用的代码。
private void comBoxActionPerformed(java.awt.event.ActionEvent evt)
{
if (comBox.getSelectedItem() == "Select . . .") {
} else if (comBox.getSelectedItem() == "Students") {
DefaultTableModel model = (DefaultTableModel) dataTable.getModel();
String sql = "select * from students";
try {
try {
Class.forName("com.mysql.jdbc.Driver");
} catch (ClassNotFoundException ex) {
Logger.getLogger(tests.class.getName()).log(Level.SEVERE, null, ex);
}
Connection connect = (Connection) DriverManager.getConnection("jdbc:mysql://localhost:3306/datavisibility","root","");
Statement statmnt = connect.createStatement();
ResultSet rslt = statmnt.executeQuery(sql);
while(rslt.next()){
String id = rslt.getString("ID");
String name = rslt.getString("Name");
String surname = rslt.getString("Surname");
String age = rslt.getString("Age");
model.addRow(new Object[]{id,name,surname,age});
}
} catch(SQLException e){
e.printStackTrace();
}
} else if (comBox.getSelectedItem() == "Teachers"){
DefaultTableModel model = (DefaultTableModel) dataTable.getModel();
String sql = "select * from teachers";
try {
try {
Class.forName("com.mysql.jdbc.Driver");
} catch (ClassNotFoundException ex) {
Logger.getLogger(tests.class.getName()).log(Level.SEVERE, null, ex);
}
Connection connect = (Connection) DriverManager.getConnection("jdbc:mysql://localhost:3306/datavisibility","root","");
Statement statmnt = connect.createStatement();
ResultSet rslt = statmnt.executeQuery(sql);
while(rslt.next()){
String id = rslt.getString("ID");
String name = rslt.getString("Name");
String surname = rslt.getString("Surname");
String age = rslt.getString("Age");
model.addRow(new Object[]{id,name,surname,age});
}
} catch(SQLException e){
e.printStackTrace();
}
} else if (comBox.getSelectedItem() == "Directors") {
DefaultTableModel model = (DefaultTableModel) dataTable.getModel();
String sql = "select * from directors";
try {
try {
Class.forName("com.mysql.jdbc.Driver");
} catch (ClassNotFoundException ex) {
Logger.getLogger(tests.class.getName()).log(Level.SEVERE, null, ex);
}
Connection connect = (Connection) DriverManager.getConnection("jdbc:mysql://localhost:3306/datavisibility","root","");
Statement statmnt = connect.createStatement();
ResultSet rslt = statmnt.executeQuery(sql);
while(rslt.next()){
String id = rslt.getString("ID");
String name = rslt.getString("Name");
String surname = rslt.getString("Surname");
String age = rslt.getString("Age");
model.addRow(new Object[]{id,name,surname,age});
}
} catch(SQLException e){
e.printStackTrace();
}
}
} `
这是output程序的内容。
我将不胜感激任何意见。谢谢!
最佳答案
您正在调用 model.addRow() ，它将向现有数据模型添加新行。它没有在任何地方清除数据模型。因此，这些行将被附加到以前的数据中。您需要将数据模型设置为新的数据模型或先删除现有数据。
关于java - 如何在 JTable 中显示数据库中的数据而不附加另一个数据库中的其他数据？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/9577582/