Question

所以，我试图通过使用文本字段从用户那里获取文本来更新数据库。

try
{
    String url = "connection info";

    Class.forName( "org.postgresql.Driver" );
    Connection connection = DriverManager.getConnection( url );
    String sql = "UPDATE equipment SET equipment_no = '" + t1.getText() + "', name = '" + t2.getText() + "', description = '" + t3.getText() + "', stock = '" + t4.getText() + "', price = '" + t5.getText() + "' WHERE equipment_id = '" + t0.getText() + "'";
    Statement stmt = connection.createStatement();

        try
        {
            stmt.executeQuery(sql);
        }
        catch(Exception ex0)
        {
            System.out.println("err");
        }

    stmt.close();
    connection.close();
    }

    catch(Exception ex)
    {
        JOptionPane.showMessageDialog(null,"Could not connect to database\nPlease try again");
    }

我遇到的问题是捕获异常ex0始终运行，即使sql语句成功执行也是如此。

更新 -

printstacktrace结果：

No results were returned by the query.
    at org.postgresql.jdbc1.AbstractJdbc1Statement.executeQuery(AbstractJdbc1Statement.java:157)
    at org.postgresql.jdbc1.AbstractJdbc1Statement.executeQuery(AbstractJdbc1Statement.java:141)
    at Edit$ButtonListener6.actionPerformed(Edit.java:387)
    at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
    at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2341)
    at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
    at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
    at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
    at java.awt.Component.processMouseEvent(Component.java:6505)
    at javax.swing.JComponent.processMouseEvent(JComponent.java:3320)
    at java.awt.Component.processEvent(Component.java:6270)
    at java.awt.Container.processEvent(Container.java:2229)
    at java.awt.Component.dispatchEventImpl(Component.java:4861)
    at java.awt.Container.dispatchEventImpl(Container.java:2287)
    at java.awt.Component.dispatchEvent(Component.java:4687)
    at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)
    at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4492)
    at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
    at java.awt.Container.dispatchEventImpl(Container.java:2273)
    at java.awt.Window.dispatchEventImpl(Window.java:2719)
    at java.awt.Component.dispatchEvent(Component.java:4687)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:735)
    at java.awt.EventQueue.access$200(EventQueue.java:103)
    at java.awt.EventQueue$3.run(EventQueue.java:694)
    at java.awt.EventQueue$3.run(EventQueue.java:692)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
    at java.awt.EventQueue$4.run(EventQueue.java:708)
    at java.awt.EventQueue$4.run(EventQueue.java:706)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:705)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)

Answer 1

使用executeUpdate：

try {
    count = stmt.executeUpdate(sql);
} catch (Exception e) {
    e.printStackTrace();
} finally {
    try {
        statement.close();
    } catch (Exception e) {
        e.printStackTrace();
    }
    try {
        connection.close();
    } catch (Exception e) {
        e.printStackTrace();
    }
}

ExecuteQuery用于返回数据的查询（例如SELECT）。顺便说一句，你也可以通过try / catch包围语句/连接。

更新sql将始终捕获异常

1 个答案: