我的更新查詢有什麼問題，參數沒有設置錯誤

Question

我是java的初學者，這是更改密碼編碼。我嘗試使用更新查詢來更新密碼。但是我的代碼出錯了。可以有人幫我找到它？我執行後，會出現錯誤：

net.ucanaccess.jdbc.UcanaccessSQLException: UCAExc:::4.0.1 Parameter not set 
    at net.ucanaccess.jdbc.UcanaccessPreparedStatement.executeUpdate(UcanaccessPreparedStatement.java:256) 
    at UserPassword.actionPerformed(UserPassword.java:142) 
    at javax.swing.AbstractButton.fireActionPerformed(Unknown Source) 
    at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source) 
    at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source) 
    at javax.swing.DefaultButtonModel.setPressed(Unknown Source) 
    at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source) 
    at java.awt.Component.processMouseEvent(Unknown Source) 
    at javax.swing.JComponent.processMouseEvent(Unknown Source) 
    at java.awt.Component.processEvent(Unknown Source) 
    at java.awt.Container.processEvent(Unknown Source) 
    at java.awt.Component.dispatchEventImpl(Unknown Source) 
    at java.awt.Container.dispatchEventImpl(Unknown Source) 
    at java.awt.Component.dispatchEvent(Unknown Source) 
    at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source) 
    at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source) 
    at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source) 
    at java.awt.Container.dispatchEventImpl(Unknown Source) 
    at java.awt.Window.dispatchEventImpl(Unknown Source) 
    at java.awt.Component.dispatchEvent(Unknown Source) 
    at java.awt.EventQueue.dispatchEventImpl(Unknown Source) 
    at java.awt.EventQueue.access$500(Unknown Source) 
    at java.awt.EventQueue$3.run(Unknown Source) 
    at java.awt.EventQueue$3.run(Unknown Source) 
    at java.security.AccessController.doPrivileged(Native Method) 
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source) 
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source) 
    at java.awt.EventQueue$4.run(Unknown Source) 
    at java.awt.EventQueue$4.run(Unknown Source) 
    at java.security.AccessController.doPrivileged(Native Method) 
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source) 
    at java.awt.EventQueue.dispatchEvent(Unknown Source) 
    at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source) 
    at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source) 
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source) 
    at java.awt.EventDispatchThread.pumpEvents(Unknown Source) 
    at java.awt.EventDispatchThread.pumpEvents(Unknown Source) 
    at java.awt.EventDispatchThread.run(Unknown Source) 
Caused by: java.sql.SQLException: Parameter not set 
    at org.hsqldb.jdbc.JDBCUtil.sqlException(Unknown Source) 
    at org.hsqldb.jdbc.JDBCUtil.sqlException(Unknown Source) 
    at org.hsqldb.jdbc.JDBCUtil.sqlException(Unknown Source) 
    at org.hsqldb.jdbc.JDBCPreparedStatement.checkParametersSet(Unknown Source) 
    at org.hsqldb.jdbc.JDBCPreparedStatement.fetchResult(Unknown Source) 
    at org.hsqldb.jdbc.JDBCPreparedStatement.executeUpdate(Unknown Source) 
    at net.ucanaccess.jdbc.ExecuteUpdate.executeWrapped(ExecuteUpdate.java:65) 
    at net.ucanaccess.jdbc.AbstractExecute.executeBase(AbstractExecute.java:208) 
    at net.ucanaccess.jdbc.ExecuteUpdate.execute(ExecuteUpdate.java:50) 
    at net.ucanaccess.jdbc.UcanaccessPreparedStatement.executeUpdate(UcanaccessPreparedStatement.java:253) 
    ... 37 more 
Caused by: org.hsqldb.HsqlException: Parameter not set 
    at org.hsqldb.error.Error.error(Unknown Source) 
    at org.hsqldb.error.Error.error(Unknown Source) 
    ... 45 more 

public void actionPerformed(ActionEvent action) 
    { 

     if(action.getSource() == backButton) 
     { 
      dispose(); 
     } 

     String userName = field1.getText(); 
     char [] s1 = field2.getPassword(); 
     char [] s2 = field3.getPassword(); 

     String userpass = new String(s1); 
     String userpass2 = new String(s2); 

      try 
      { 
       String UpdateQuery = null; 
       PreparedStatement st = null; 

       Connection connect = DriverManager.getConnection("jdbc:ucanaccess://Database.accdb"); 

       if(action.getSource() == changeButton) 
       { 
        UpdateQuery = "UPDATE STUDENT SET StudentID = ?, Password = ? WHERE StudentID = ?"; 
        st = connect.prepareStatement(UpdateQuery); 

        if(userpass.equals(userpass2)) 
        { 
           st.setString(1, userName); 
           st.setString(2, userpass2); 

           st.executeUpdate(); 

           JOptionPane.showMessageDialog(this,"Username and Password changed!","Student",JOptionPane.INFORMATION_MESSAGE); 
           dispose(); 
           UserPage up = new UserPage(null); 

           connect.close(); 

        } 


         else if(userpass != userpass2) 
         { 
          JOptionPane.showMessageDialog(this,"Password not match!","Password error",JOptionPane.ERROR_MESSAGE); 
         } 
       } 


      } 
      catch (SQLException e1) 
      { 
       e1.printStackTrace(); 
      } 
       reset(); 

     } 

} 

Answer 1

你有三個？但只有兩個參數設置。你錯過了第三個參數。

st.setString(3, userId);