驗證部分出現問題，沒有關于空字段的消息顯示。立即提供幫助private void addbtnActionPerformed(java.awt.event.ActionEvent evt) { try{ Class.forName("com.mysql.cj.jdbc.Driver"); Connection con =DriverManager.getConnection("jdbc:mysql://localhost:3306/dbfinance","root","1234"); String sql="insert into util(type_,due_date,month_,amount,units,status_) values(?,?,?,?,?,?)"; PreparedStatement pstm =con.prepareStatement(sql); pstm.setString(1,electype.getSelectedItem().toString()); pstm.setString(2,date.getText().toString()); pstm.setString(3,jComboBox1.getSelectedItem().toString()); pstm.setDouble(4,Double.parseDouble(amount.getText())); pstm.setString(5,unit.getText()); pstm.setString(6,status.getText()); pstm.executeUpdate(); JOptionPane.showMessageDialog(null, "success"); con.close(); }catch(Exception e){ JOptionPane.showMessageDialog(null,e); } if(amount.getText().isEmpty()||unit.getText().isEmpty()||status.getText().isEmpty()){ JOptionPane.showMessageDialog(null,"please enter data"); // errorname2.setText("fill this field"); } }
2 回答
江戶川亂折騰
TA貢獻1851條經驗 獲得超5個贊
在驗證之前，您不應該將數據插入數據庫。僅當數據不為空時才插入數據。至于檢查數據是否為空，最好修剪文本，以便在給定的空白表示某個值的情況下，任何空白都會被修剪掉。
if(amount.getText().trim().isEmpty()||unit.getText().trim().isEmpty()||
status.getText().trim().isEmpty()){
JOptionPane.showMessageDialog(null,"please enter data");
// errorname2.setText("fill this field");
}
請確保您將修剪后的數據插入到數據庫中。
慕村225694
TA貢獻1880條經驗 獲得超4個贊
在應用語句之前嘗試驗證您的金額字段是否為空try-catch：
if(amount.getText().isEmpty()||unit.getText().isEmpty()||status.getText().isEmpty()){
JOptionPane.showMessageDialog(null,"please enter data");
// errorname2.setText("fill this field");
}else{
try{
Class.forName("com.mysql.cj.jdbc.Driver");
Connection con =DriverManager.getConnection("jdbc:mysql://localhost:3306/dbfinance","root","1234");
String sql="insert into util(type_,due_date,month_,amount,units,status_) values(?,?,?,?,?,?)";
PreparedStatement pstm =con.prepareStatement(sql);
pstm.setString(1,electype.getSelectedItem().toString());
pstm.setString(2,date.getText().toString());
pstm.setString(3,jComboBox1.getSelectedItem().toString());
pstm.setDouble(4,Double.parseDouble(amount.getText()));
pstm.setString(5,unit.getText());
pstm.setString(6,status.getText());
pstm.executeUpdate();
JOptionPane.showMessageDialog(null, "success");
con.close();
}catch(Exception e){
JOptionPane.showMessageDialog(null,e);
}
}
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