Question

我有3个表（医生，护士，患者），它们的ID开头都不同，医生的ID开头为101，护士的ID开头为102，患者的开头为200。我想根据其ID的开头更改密码。在我的JFrame中，我有5个JComponents，4个Jtextfields，1个Jbutton 1个Jtextfields作为id（名称：idField）当前密码的1个Jtextfields（名称：currentPass） 2个用于新密码的Jtextfields（名称：newPass1，newPass2） 1个用于操作的Jbutton（名称：changeButton）

我在代码中做了2种不同的方式，但两种方式都不适合我。您能帮我解决这个问题吗？

第一种方式：

private void changeButtonActionPerformed(java.awt.event.ActionEvent evt) {                                             
       id=idField.getText();
       newpass1=newPass1.getText();
       newpass2=newPass2.getText();

        try {
        con = DriverManager.getConnection("jdbc:derby://localhost:1527/hj", "xxx", "xxx");
        st = con.createStatement();

        if (newpass1.equals(newpass2)){


          ResultSet rs = st.executeQuery("update patient set patient_Password="+ newpass1 +" where patient_Id="+id+" and patient_Id like '200%'");  
          JOptionPane.showMessageDialog(this , "Successfully changed", "Patient password successfuly changed !",JOptionPane.PLAIN_MESSAGE);

          ResultSet rs1 = st.executeQuery("update Nurse set nurse_password="+ newpass1 +" where nurse_id="+id+" and nurse_id like '102%'");
            JOptionPane.showMessageDialog(this , "Successfully changed", "Nurse password successfuly changed !",JOptionPane.PLAIN_MESSAGE);

            ResultSet rs2 = st.executeQuery("update doctor set doctor_password="+ newpass1 +" where doctor_id="+id+" and doctor_id like '101%'");
            JOptionPane.showMessageDialog(this , "Successfully changed", "Doctor password successfuly changed !",JOptionPane.PLAIN_MESSAGE);

        } else 
            JOptionPane.showMessageDialog(this , "Not equal", "Your new passwords are not equal!! , try again",JOptionPane.ERROR_MESSAGE );
       }catch (Exception x){
           JOptionPane.showMessageDialog(this, x.getStackTrace());
       }
    }

第二种方式：

 private void changeButtonActionPerformed(java.awt.event.ActionEvent evt) {                                             
       id=idField.getText();
       newpass1=newPass1.getText();
       newpass2=newPass2.getText();

        try {
        con = DriverManager.getConnection("jdbc:derby://localhost:1527/hj", "xxx", "xxx");
        st = con.createStatement();

        if (newpass1.equals(newpass2)){

        if (id.startsWith("200")){
          ResultSet rs = st.executeQuery("update patient set patient_Password="+ newpass1 +" where patient_Id="+id+"");  
          JOptionPane.showMessageDialog(this , "Successfully changed", "Patient password successfuly changed !",JOptionPane.PLAIN_MESSAGE);
        } 
        else if (id.startsWith("102")){
          ResultSet rs = st.executeQuery("update Nurse set nurse_password="+ newpass1 +" where nurse_id="+id+"");
            JOptionPane.showMessageDialog(this , "Successfully changed", "Nurse password successfuly changed !",JOptionPane.PLAIN_MESSAGE);
                }
        else if (id.startsWith("101")){
            ResultSet rs = st.executeQuery("update doctor set doctor_password="+ newpass1 +" where doctor_id="+id+"");
            JOptionPane.showMessageDialog(this , "Successfully changed", "Doctor password successfuly changed !",JOptionPane.PLAIN_MESSAGE);
        }

        } else 
            JOptionPane.showMessageDialog(this , "Not equal", "Your new passwords are not equal!! , try again",JOptionPane.ERROR_MESSAGE );
       }catch (Exception x){
           JOptionPane.showMessageDialog(this, x.getStackTrace());
       }
    }

Answer 1

请使用$responstable！

PreparedStatement

通过串联查询，您将得到if (id.startsWith("200")){ try (PreparedStatement pstmt = conn.prepareStatement("UPDATE patient SET patient_passwort=? WHERE patient_id=?");) { pstmt.setString(1, newpass1); pstmt.setString(2, id); int rows = pstmt.executeUpdate(); JOptionPane.showMessageDialog(this , "Successfully changed", "Patient password successfuly changed! (updated rows: "+rows+")", JOptionPane.PLAIN_MESSAGE); } }。未引用新密码（此处为update patient set patient_Password=abcdefghi where patient_Id=200340 and patient_Id like '200%'），这对于查询中的字符串是必需的。 abcdefghi也未加引号，但可能是数字字段，不必加引号。

顺便说一句：

不需要查询部分patient_id。
您应该关闭任何PreparedStatement / Statement实例，这可以通过使用try-with-resources（patient_id like '200%'）来完成。 try (PreparedStatement xxx = ...) { ... your code } // closes automatically和Connection也是如此。
由于ResultSet是整数，因此您可能需要这样使用它：id

提示：如果使用Apache commons-dbutils，您将更加轻松自在。例如int updId = Integer.parseInt(id); ... pstmt.setInt(2, updId); ...

org.apache.commons.dbutils.QueryRunner

根据不同的ID开头从数据库更改密码

1 个答案: