ORDER BY子句用于对查询结果集进行排序,ORDER BY中每个表达式由列名或列序号(从1开始)组成。
[ ORDER BY expression[ ASC | DESC ][ NULLS FIRST | NULLS LAST ] [ LIMIT { count | ALL } ]
[ ORDER BY expression
[ ASC | DESC ]
[ NULLS FIRST | NULLS LAST ]
[ LIMIT { count | ALL } ]