RETENTION

SinceVersion 1.2.0

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

1. DROP TABLE IF EXISTS retention_test;

3. CREATE TABLE retention_test(
4. `uid` int COMMENT 'user id',
5. `date` datetime COMMENT 'date time'
6. )
7. DUPLICATE KEY(uid)
8. DISTRIBUTED BY HASH(uid) BUCKETS 3
9. PROPERTIES (
10. "replication_num" = "1"
11. );

13. INSERT into retention_test (uid, date) values (0, '2022-10-12'),
14. (0, '2022-10-13'),
15. (0, '2022-10-14'),
16. (1, '2022-10-12'),
17. (1, '2022-10-13'),
18. (2, '2022-10-12');

20. SELECT * from retention_test;

22. +------+---------------------+
23. | uid  | date                |
24. +------+---------------------+
25. |    0 | 2022-10-14 00:00:00 |
26. |    0 | 2022-10-13 00:00:00 |
27. |    0 | 2022-10-12 00:00:00 |
28. |    1 | 2022-10-13 00:00:00 |
29. |    1 | 2022-10-12 00:00:00 |
30. |    2 | 2022-10-12 00:00:00 |
31. +------+---------------------+

33. SELECT
34. uid,
35. retention(date = '2022-10-12')
36. AS r
37. FROM retention_test
38. GROUP BY uid
39. ORDER BY uid ASC;

41. +------+------+
42. | uid  | r    |
43. +------+------+
44. |    0 | [1]  |
45. |    1 | [1]  |
46. |    2 | [1]  |
47. +------+------+

49. SELECT
50. uid,
51. retention(date = '2022-10-12', date = '2022-10-13')
52. AS r
53. FROM retention_test
54. GROUP BY uid
55. ORDER BY uid ASC;

57. +------+--------+
58. | uid  | r      |
59. +------+--------+
60. |    0 | [1, 1] |
61. |    1 | [1, 1] |
62. |    2 | [1, 0] |
63. +------+--------+

65. SELECT
66. uid,
67. retention(date = '2022-10-12', date = '2022-10-13', date = '2022-10-14')
68. AS r
69. FROM retention_test
70. GROUP BY uid
71. ORDER BY uid ASC;

73. +------+-----------+
74. | uid  | r         |
75. +------+-----------+
76. |    0 | [1, 1, 1] |
77. |    1 | [1, 1, 0] |
78. |    2 | [1, 0, 0] |
79. +------+-----------+

keywords

RETENTION