Question

我正在为我们在学校的项目创建学生资料，这是我第一次这样做。

这是我对我在netbeans中创建的jTable（鼠标单击）的查询

        int row = jTable1.getSelectedRow();
        String tc = jTable1.getModel().getValueAt(row, 0).toString();
        try {
            String query ="select * from CAREPOINT_STUDENT where NAME="+tc+" ";
            pst= (OraclePreparedStatement) ungabelio1.prepareStatement(query);
            rs = (OracleResultSet) pst.executeQuery();

            if(rs.next()){

                String NAME_ID = rs.getString("NAME");
                String AGE_ID = rs.getString("AGE");
                String ADDRESS_ID = rs.getString("ADDRESS");
                String NUM_ID = rs.getString("NUM");
                String COURSE_ID = rs.getString("COURSE");
                String SPECIAL_ID = rs.getString("SPECIAL");
                String SCHOOL_ID = rs.getString("SCHOOL");
                String DOWNPAY_ID = rs.getString("DOWNPAY");
                String DISCOUNT_ID = rs.getString("DISCOUNT");
                String BALANCE_ID = rs.getString("BALANCE");
                String REVSCHED_ID = rs.getString("REVSCHED");
                String EMAIL_ID = rs.getString("EMAIL");

                NAME.setText(NAME_ID);
                AGE.setText(AGE_ID);
                ADDRESS.setText(ADDRESS_ID);
                NUM.setText(NUM_ID);
                COURSE.setText(COURSE_ID);
                SPECIAL.setText(SPECIAL_ID);
                SCHOOL.setText(SCHOOL_ID);
                DOWNPAY.setText(DOWNPAY_ID);
                DISCOUNT.setText(DISCOUNT_ID);
                BALANCE.setText(BALANCE_ID);
                REVSCHED.setText(REVSCHED_ID);
                EMAIL.setText(EMAIL_ID);

            }

        } catch (Exception e) {
            JOptionPane.showMessageDialog(null, e);
        }

    }

当我运行程序并尝试单击在jtable内创建并打印（mouseclicked）并打印的数据（学生档案，例如姓名，年龄，学校等）时，出现此问题“ ORA-00933： SQL命令未正确结束”

除此之外，我还有另一个问题，我创建了2个名为“ DELETE”的jbutton，这意味着它将删除我填写的数据（学生资料）和“ UPDATE”，这意味着重新编辑数据（学生资料）我填满了。

这是我在netbeans中对“ DELETE” jbutton的查询

try {
            String query;
            query = "DELETE FROM CAREPOINT_STUDENT where NAME="+NAME.getText()+" ";
            pst= (OraclePreparedStatement) ungabelio1.prepareStatement(query);

            pst.execute();
            JOptionPane.showMessageDialog(null, "Successfully deleted!");
            fetch();

        } catch (Exception e) {

            JOptionPane.showMessageDialog(null, e);
        }
    }

这是我在netbeans中的“ UPDATE” jbutton的查询

try {
            String query;
            query = "update CAREPOINT_STUDENT set AGE=?,ADDRESS=?,NUM=?,COURSE=?,SPECIAL=?,SCHOOL=?,DOWNPAY=?,DISCOUNT=?,BALANCE=?,REVSCHED=?,EMAIL=? where NAME="+NAME.getText()+"";
            pst= (OraclePreparedStatement) ungabelio1.prepareStatement(query);

            pst.setString(1,AGE.getText());
            pst.setString(2,ADDRESS.getText());
            pst.setString(3, NUM.getText());
            pst.setString(4, COURSE.getText());
            pst.setString(5, SPECIAL.getText());
            pst.setString(6, SCHOOL.getText());
            pst.setString(7, DOWNPAY.getText());
            pst.setString(8, DISCOUNT.getText());
            pst.setString(9, BALANCE.getText());
            pst.setString(10, REVSCHED.getText());
            pst.setString(11, EMAIL.getText());

            pst.executeUpdate();
            JOptionPane.showMessageDialog(null, "Successfully updated!");
            fetch();

        } catch (Exception e){

            JOptionPane.showMessageDialog(null, e);
        }
    }

当我运行程序并单击这两个按钮时，出现相同的问题“ ORA-00936：缺少表达式”

我真的很感谢，希望有人能帮助我解决这个问题。这样我就可以对sql / oracle有所了解。

对不起，我的英语不好。

Answer 1

避免将参数串联为字符串；使用准备好的语句。

否则，您将遇到各种麻烦，例如转义特殊字符，SQL注入等问题。

例如，运行SQL语句的一种更安全的方法可能是：

String query = "select * from CAREPOINT_STUDENT where NAME = ?";
pst = (OraclePreparedStatement) ungabelio1.prepareStatement(query);
pst.setString(1, tc);
rs = (OracleResultSet) pst.executeQuery();

注意：在需要执行一些动态SQL的情况下，将SQL语句作为字符串进行组装仍然很有用。即使这样，也可以使用?作为参数，并按照上面的说明应用它们。

Answer 2

您可能需要一些额外的单引号，因此查询将显示为：

select * from CAREPOINT_STUDENT where NAME='Entered name';

调整您的代码：

String query ="select * from CAREPOINT_STUDENT where NAME='"+tc+"' ";

如何在SQL / Oracle中解决“ ORA-00933＆ORA-00936”？

2 个答案: