hive DDL语法汇总
１、对表重命名
hive> ALTER TABLE table_name RENAME TO new_table_name;
2、修改表备注
hive> ALTER TABLE table_name SET TBLPROPERTIES ('comment' = new_comment);
3、添加表分区
hive> ALTER TABLE table_name ADD [IF NOT EXISTS] PARTITION partition_spec
[LOCATION
'location1'
] partition_spec [LOCATION
'location2'
] ...;
hive> ALTER TABLE page_view
ADD
PARTITION (dt=
'2008-08-08'
, country=
'us'
) location
'/path/to/us/part080808'
PARTITION (dt=
'2008-08-09'
, country=
'us'
) location
'/path/to/us/part080809'
;
4、对表分区进行重命名
hive> ALTER TABLE table_name PARTITION partition_spec RENAME TO PARTITION partition_spec
5、交换分区（0.12版本以上支持）
两个表结构必需相同，
hive> ALTER TABLE table_name_1 EXCHANGE PARTITION (partition_spec) WITH TABLE table_name_2;
6、删除表分区
ALTER TABLE table_name DROP [IF EXISTS] PARTITION partition_spec[, PARTITION partition_spec, ...]
[IGNORE PROTECTION] [PURGE];
注意：PURGE 参数是在Hive
1.2
.
0及以后的版本才支持，加上该参数则直接删除表分区，而不是将数据放入垃圾回收站；如果没加purge参数，则删掉的分区进入回收站
7、恢复分区
MSCK REPAIR TABLE table_name;
8、归档分区
ALTER TABLE table_name ARCHIVE PARTITION partition_spec;
ALTER TABLE table_name UNARCHIVE PARTITION partition_spec;
9、修改列
ALTER TABLE table_name [PARTITION partition_spec] CHANGE [COLUMN] col_old_name col_new_name column_type [COMMENT col_comment] [FIRST|AFTER column_name] [CASCADE|RESTRICT];
例子：
CREATE TABLE test_change (a
int
, b
int
, c
int
);
// First change column a's name to a1.
ALTER TABLE test_change CHANGE a a1 INT;
// Next change column a1's name to a2, its data type to string, and put it after column b.
ALTER TABLE test_change CHANGE a1 a2 STRING AFTER b;
// The new table's structure is: b int, a2 string, c int.
// Then change column c's name to c1, and put it as the first column.
ALTER TABLE test_change CHANGE c c1 INT FIRST;
// The new table's structure is: c1 int, b int, a2 string.
10、增加列
ALTER TABLE table_name [PARTITION partition_spec]
ADD|REPLACE COLUMNS (col_name data_type [COMMENT col_comment], ...)
[CASCADE|RESTRICT]
hive> alter table table_name add columns(new_column_name column_type)
11、删除列
原表有三列(a int, b int ,c int);
ALTER TABLE test_change REPLACE COLUMNS (a int, b int)
注：删除列时，如果是把前面的列删除，hive只是将列名往前移，数据并没有动，这个要小心
