COLLECT_SET(col)

• 定义：collect_set(col)
• 说明：将一列的值去重后返回，col的数据类型必须是基本类型
• 返回值类型：array
• 案例

SELECT COLLECT_SET(name) FROM t;

+------------------------------------------------------+
|                        _c0                           |
+------------------------------------------------------+
| ["TOM","TONY","KATE","JACK","JACKSON","BOB","ALLEN"] |
+------------------------------------------------------+

COLLECT_LIST(col)

• 定义：collect_list(col)
• 说明：将一列的值组成数组后返回，不去重，col的数据类型必须是基本类型
• 返回值类型：array
• 可用版本：hive-0.13.0+
• 案例

SELECT COLLECT_LIST(name) FROM t;

+------------------------------------------------------+
|                        _c0                           |
+------------------------------------------------------+
| ["TOM","TONY","KATE","JACK","JACKSON","BOB","ALLEN"] |
+------------------------------------------------------+