sql中desc的妙用
很多情况下对表内部结构不熟悉，想看下我创建的表里面又多少表明，又想他按照首字母的规律排列，
这时候就要用desc +表名了。
desc t_bike_info;
hive> desc t_bike_info; OK guid string bike_no string city_guid string city_name string produce_time string produce_batch_number string hardware_type int bike_sim string bike_color int bike_key string control_person_id string online_time string create_date string update_date string create_user_guid string update_user_guid string test_time string unqualified_reason string service_area_id string service_area_name string sum_running_distance int lng double lat double user_last_point_type int user_last_point_time string hardware_version string firmware_version string city_code string pt string
1 hive> desc t_bike_info; 2 OK 3 guid string 4 bike_no string 5 city_guid string 6 city_name string 7 produce_time string 8 produce_factory_name string 9 produce_factory_guid string 10 produce_batch_number string 11 hardware_type int 12 bike_sim string 13 bike_color int 14 bike_type int 15 bike_status int 16 bike_running_status int 17 bike_hw_status int 18 bike_chip_status int 19 bike_key string 20 control_person_id string 21 control_person_name string 22 online_time string 23 create_date string 24 update_date string 25 create_user_guid string 26 update_user_guid string 27 test_time string 28 test_user_guid string 29 test_user_name string 30 unqualified_reason string 31 service_area_id string 32 service_area_name string 33 sum_running_distance int 34 lng double 35 lat double 36 user_last_point_type int 37 user_last_point_time string 38 hardware_version string 39 firmware_version string 40 city_code string 41 pt string
