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RETENTION

RETENTION

RETENTION

description

Syntax

retention(event1, event2, ... , eventN);

留存函数将一组条件作为参数,类型为1到32个UInt8类型的参数,用来表示事件是否满足特定条件。 任何条件都可以指定为参数.

除了第一个以外,条件成对适用:如果第一个和第二个是真的,第二个结果将是真的,如果第一个和第三个是真的,第三个结果将是真的,等等。

简单来讲,返回值数组第1位表示event1的真假,第二位表示event1真假与event2真假相与,第三位表示event1真假与event3真假相与,等等。如果event1为假,则返回全是0的数组。

Arguments

event — 返回UInt8结果(1或0)的表达式.

Returned value

由1和0组成的最大长度为32位的数组,最终输出数组的长度与输入参数长度相同。

1 — 条件满足。

0 — 条件不满足

example

DROP TABLE IF EXISTS retention_test;

CREATE TABLE retention_test(
`uid` int COMMENT 'user id',
`date` datetime COMMENT 'date time'
)
DUPLICATE KEY(uid)
DISTRIBUTED BY HASH(uid) BUCKETS 3
PROPERTIES (
"replication_num" = "1"
);

INSERT into retention_test (uid, date) values (0, '2022-10-12'),
(0, '2022-10-13'),
(0, '2022-10-14'),
(1, '2022-10-12'),
(1, '2022-10-13'),
(2, '2022-10-12');

SELECT * from retention_test;

+------+---------------------+
| uid | date |
+------+---------------------+
| 0 | 2022-10-14 00:00:00 |
| 0 | 2022-10-13 00:00:00 |
| 0 | 2022-10-12 00:00:00 |
| 1 | 2022-10-13 00:00:00 |
| 1 | 2022-10-12 00:00:00 |
| 2 | 2022-10-12 00:00:00 |
+------+---------------------+

SELECT
uid,
retention(date = '2022-10-12')
AS r
FROM retention_test
GROUP BY uid
ORDER BY uid ASC;

+------+------+
| uid | r |
+------+------+
| 0 | [1] |
| 1 | [1] |
| 2 | [1] |
+------+------+

SELECT
uid,
retention(date = '2022-10-12', date = '2022-10-13')
AS r
FROM retention_test
GROUP BY uid
ORDER BY uid ASC;

+------+--------+
| uid | r |
+------+--------+
| 0 | [1, 1] |
| 1 | [1, 1] |
| 2 | [1, 0] |
+------+--------+

SELECT
uid,
retention(date = '2022-10-12', date = '2022-10-13', date = '2022-10-14')
AS r
FROM retention_test
GROUP BY uid
ORDER BY uid ASC;

+------+-----------+
| uid | r |
+------+-----------+
| 0 | [1, 1, 1] |
| 1 | [1, 1, 0] |
| 2 | [1, 0, 0] |
+------+-----------+

keywords

RETENTION