使用Java GUI从数据库中删除或插入数据库

我的代码可以很好地执行select语句，但由于某些原因，我无法使insert和delete段正常工作。我相信他们应该是一样的，对吗？我只是不知道我的代码出了什么问题

    else if (e.getSource() == executeButton) {
        //Create a statement
        if (enterSQLText.getText().toLowerCase().contains("select")){
            try{
                String commandString = enterSQLText.getText();
                Statement statement = conn.createStatement();
                //Execute a statement
                ResultSet resultSet = statement.executeQuery(commandString);
                //Process query results
                ResultSetMetaData metaData = resultSet.getMetaData();
                int numberOfColumns = metaData.getColumnCount();

                for(int i = 1; i<= numberOfColumns; i++){
                  executionResultText.append(metaData.getColumnName(i) + "\t");
                  System.out.printf("%20s\t", metaData.getColumnName(i));
                }
                executionResultText.append("\n");
                System.out.println();

                while (resultSet.next()){
                    for (int i = 1; i <= numberOfColumns; i++){
                        executionResultText.append(resultSet.getObject(i).toString() + "\t");
                        System.out.printf("%20s\t", resultSet.getObject(i));
                    }
                    executionResultText.append("\n");
                    System.out.println();
                 }
                 System.out.println("Execute Button Works!");
              }
              catch (Exception h){
                h.printStackTrace();
              }
        }
        else if (enterSQLText.getText().toLowerCase().contains("delete") || enterSQLText.getText().toLowerCase().contains("insert")) {
            try {
                String commandString = enterSQLText.getText();
                Statement statement = conn.prepareStatement(commandString);
                ResultSet resultSet = statement.executeUpdate(commandString);
            }
            catch (Exception l){
                l.printStackTrace();
            }
        }
        else {
            executionResultText.setText("Sorry, that is not a valid command");
            System.out.println("Not a vilid command.");
        }
    }

当我尝试执行insert或delete命令时，会得到如下堆栈跟踪：

com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Duplicate entry 'Mark Renshaw' for key 'PRIMARY'
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
    at java.lang.reflect.Constructor.newInstance(Unknown Source)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
    at com.mysql.jdbc.Util.getInstance(Util.java:386)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1040)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4096)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4028)
    at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2490)
    at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2651)
    at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2728)
    at com.mysql.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1811)
    at com.mysql.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1725)
    at ConnectToDB.actionPerformed(ConnectToDB.java:203)
    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$200(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$1.doIntersectionPrivilege(Unknown Source)
    at java.security.ProtectionDomain$1.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$1.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)

无论我对该段做了什么，它要么阻止我连接到数据库，要么抛出一个错误

com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException:key“PRIMARY”的重复条目“Mark Renshaw”

这是很明显的。您正在尝试为主键插入重复项。主键是唯一的，不能使用同一个键两次

您可能不希望名称列成为主键。为此使用自动生成的ID列

---

否则，请删除包含“Mark Renshaw”的列并再次运行代码。但是，当你在同一个名称上运行它两次时，它只会运行一次。

你能分享相关的堆栈跟踪吗？考虑添加你的StAcTrack。谢谢大家，我用更详细的方式更新了这个问题。复制键很清楚。您的表中还有一行具有相同的主键。最后我想了很久。下面是删除和插入的工作段。else if（enterSQLText.getText（）.toLowerCase（）.contains（“delete”）| | enterSQLText.getText（）.toLowerCase（）.contains（“insert”）{try{String commandString=enterSQLText.getText（）；conn.prepareStatement（commandString）.executeUpdate（commandString）}catch（异常l）{l.printStackTrace（）谢谢你的帮助！

com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Duplicate entry 'Mark Renshaw' for key 'PRIMARY'
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
    at java.lang.reflect.Constructor.newInstance(Unknown Source)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
    at com.mysql.jdbc.Util.getInstance(Util.java:386)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1040)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4096)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4028)
    at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2490)
    at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2651)
    at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2728)
    at com.mysql.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1811)
    at com.mysql.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1725)
    at ConnectToDB.actionPerformed(ConnectToDB.java:203)
    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$200(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$1.doIntersectionPrivilege(Unknown Source)
    at java.security.ProtectionDomain$1.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$1.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)