1、Create [EXTERNAL] TABLE [IF NOT EXISTS] table_name
external 创建外部表， location为外部表存放位置，Hive 创建内部表时，
会把数据移到数据仓库指向的路径，如果创建了外部表，仅记录数据所在的路径，
不对数据位置做更改。在删除表的时候，内部表的元数据和数 据会被一起删除，而外部表只删除元数据，不删除数据。
[(col_name data_type [COMMENT col_comment], ...)]
[COMMENT table_comment]
[PARTITIONED BY (col_name data_type [COMMENT col_comment], ...)]
[CLUSTERED BY (col_name, col_name, ...) [SORTED BY (col_name [ASC|DESC], ...)] INTO num_buckets BUCKETS]
[ROW FORMAT row_format]
[STORED AS file_format]
[LOCATION hdfs_path]
