percentile_empty

构造一个 PERCENTILE 值，该值用于在使用 Stream Load 或 INSERT INTO 进行数据加载时填充空值。

语法

PERCENTILE_EMPTY();

参数

None (无)

返回值

返回一个 PERCENTILE 值。

示例

创建一个表。percent 列是一个 PERCENTILE 列。

CREATE TABLE `aggregate_tbl` (
  `site_id` largeint(40) NOT NULL COMMENT "id of site",
  `date` date NOT NULL COMMENT "time of event",
  `city_code` varchar(20) NULL COMMENT "city_code of user",
  `pv` bigint(20) SUM NULL DEFAULT "0" COMMENT "total page views",
  `percent` PERCENTILE PERCENTILE_UNION COMMENT "others"
) ENGINE=OLAP
AGGREGATE KEY(`site_id`, `date`, `city_code`)
COMMENT "OLAP"
DISTRIBUTED BY HASH(`site_id`)
PROPERTIES ("replication_num" = "3");

将数据插入到表中。

INSERT INTO aggregate_tbl VALUES
(5, '2020-02-23', 'city_code', 555, percentile_empty());