从表中获取特定行时，Java JDBC程序引发SQL语法错误

Question

我有一个名为“ airplane”的数据库，其中有一个名为timetable的表。 定时表格的文字类型为城市列

                    Connection conn0=null;
                    PreparedStatement st0=null;
                    String sql0="SELECT FROM timetable where fromcity=?";

                try{
                        Class.forName("com.mysql.jdbc.Driver");
                        conn0=DriverManager.getConnection(DB_URL,USER,PASS);
                        st0=conn0.prepareStatement(sql0);
                        st0.setString(1,city[i]);
                        ResultSet rs0=st0.executeQuery();

                        if(rs0.next())
                        {
                            System.out.println("flight exists");
                        }

                        else
                        {
                            System.out.println("fight does not exist");
                        }


                    }
                    catch(Exception et)
                    {
                        System.out.println("Error"+et.getMessage());
                    }

我收到错误消息：

为什么我得到这个错误

You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'FROM timetable where fromcity='1'' at line 1

Answer 1

您忘记在查询中写列名。

做了，

SELECT * FROM timetable where fromcity=?"

代替，

SELECT FROM timetable where fromcity=?"