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您好，我正在尝试从数据库中获取记录，而我正在使用一个基于该选择的组合框我想从文本字段中的同一个表中获取相关记录..但不幸的是我得到了错误..谁能给我片段我在哪里代码错误？

 try {
        Class.forName("com.mysql.jdbc.Driver");
        con = (Connection) DriverManager.getConnection("jdbc:mysql://localhost:3306/testdatabase", "root", "ubuntu123");
        Statement st = con.createStatement();
        ResultSet rs = st.executeQuery("Select productname,quantity from productorder");

        // ResultSet rs1 = st.executeQuery("Select quantity from productorder");

        while (rs.next()) {

            jComboBox1.addItem(rs.getString("productname"));

        }

        jComboBox1.addItemListener(new ItemListener() {

            public void itemStateChanged(ItemEvent ie) {

                try {
                    String str = (String) jComboBox1.getSelectedItem();
                    //Statement st1 = con.createStatement();
                    PreparedStatement stmt = (PreparedStatement) con.prepareStatement("Select * from productorder where productname=?");
                    stmt.setString(1, str);
                    ResultSet rs1 = stmt.executeQuery();
                    jTextField2.setText(str);

                    Integer qty=rs1.getInt(1); // Error in this line at com.mylogin.Testingproductmaster$1.itemStateChanged(Testingproductmaster.java:58)

                  jTextField1.setText(qty.toString());

                } catch (SQLException ex) {
                      Logger.getLogger(Testingproductmaster.class.getName()).log(Level.SEVERE, null, ex);
                }

全栈跟踪

  18 Apr, 2013 5:14:33 PM com.mylogin.Testingproductmaster$1 itemStateChanged
  SEVERE: null
  java.sql.SQLException: Invalid value for getInt() - 'TCS'

  at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1075)

at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:989)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:984)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:929)
at com.mysql.jdbc.ResultSetImpl.getInt(ResultSetImpl.java:2725)
at com.mylogin.Testingproductmaster$1.itemStateChanged(Testingproductmaster.java:62)
at javax.swing.JComboBox.fireItemStateChanged(JComboBox.java:1222)
at javax.swing.JComboBox.selectedItemChanged(JComboBox.java:1279)
at javax.swing.JComboBox.contentsChanged(JComboBox.java:1326)
at javax.swing.AbstractListModel.fireContentsChanged(AbstractListModel.java:117)
at javax.swing.DefaultComboBoxModel.setSelectedItem(DefaultComboBoxModel.java:105)
at javax.swing.JComboBox.setSelectedItem(JComboBox.java:574)
at javax.swing.JComboBox.setSelectedIndex(JComboBox.java:620)
at javax.swing.plaf.basic.BasicComboPopup$Handler.mouseReleased(BasicComboPopup.java:831)
at java.awt.AWTEventMulticaster.mouseReleased(AWTEventMulticaster.java:290)
at java.awt.Component.processMouseEvent(Component.java:6389)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3268)
at javax.swing.plaf.basic.BasicComboPopup$1.processMouseEvent(BasicComboPopup.java:497)
at java.awt.Component.processEvent(Component.java:6154)
at java.awt.Container.processEvent(Container.java:2045)
at java.awt.Component.dispatchEventImpl(Component.java:4750)
at java.awt.Container.dispatchEventImpl(Container.java:2103)
at java.awt.Component.dispatchEvent(Component.java:4576)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4633)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4297)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4227)
at java.awt.Container.dispatchEventImpl(Container.java:2089)
at java.awt.Window.dispatchEventImpl(Window.java:2518)
at java.awt.Component.dispatchEvent(Component.java:4576)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:672)
at java.awt.EventQueue.access$400(EventQueue.java:96)
at java.awt.EventQueue$2.run(EventQueue.java:631)
at java.awt.EventQueue$2.run(EventQueue.java:629)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:105)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:116)
at java.awt.EventQueue$3.run(EventQueue.java:645)
at java.awt.EventQueue$3.run(EventQueue.java:643)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:105)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:642)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:275)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:200)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:190)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:185)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:177)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:138)
4

1 回答 1

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确保将ResultSet光标移到JComboBox ItemListener

ResultSet rs1 = stmt.executeQuery();

if (rs1.next()) {
    Integer qty = rs1.getInt(1);
    ...
}

请注意，这将使用检索到的第一条记录。如果不是唯一的，则可能需要更具体的WHERE子句从数据库查询中返回单个记录。productname

编辑：从此错误

java.sql.SQLException: Invalid value for getInt() - 'TCS'

在列索引 1 处返回的值实际上不是有效的整数值（似乎是文本类型）。检查调用你的 SQL

Select * from productorder where productname='<Some Product Here>'

在您的 SQL 客户端中，并确保您从正确的索引中读取以匹配您的qty整数变量。

如果数量是唯一要检索的数据，则可以优化查询以仅返回该信息

Select quantity from productorder where productname=?
于 2013-04-17T19:52:16.770 回答