SQL-ORDER BY 多字段排序(升序、降序)
ORDER
BY
_column1, _column2; /* _column1升序,_column2升序 */
ORDER
BY
_column1, _column2
DESC
; /* _column1升序,_column2降序 */
ORDER
BY
_column1
DESC
, _column2 ; /* _column1降序,_column2升序 */
ORDER
BY
_column1
DESC
, _column2
DESC
; /* _column1降序,_column2降序 */