array_with_constant

SinceVersion 1.2.0

array_with_constant array_repeat

description

Syntax

1. ARRAY<T> array_with_constant(n, T)
2. ARRAY<T> array_repeat(T, n)

返回一个数组, 包含n个重复的T常量。array_repeat与array_with_constant功能相同，用来兼容hive语法格式。

notice

仅支持向量化引擎中使用

example

1. mysql> set enable_vectorized_engine=true;

3. mysql> select array_with_constant(2, "hello"), array_repeat("hello", 2);
4. +---------------------------------+--------------------------+
5. | array_with_constant(2, 'hello') | array_repeat('hello', 2) |
6. +---------------------------------+--------------------------+
7. | ['hello', 'hello']              | ['hello', 'hello']       |
8. +---------------------------------+--------------------------+
9. 1 row in set (0.04 sec)

11. mysql> select array_with_constant(3, 12345), array_repeat(12345, 3);
12. +-------------------------------+------------------------+
13. | array_with_constant(3, 12345) | array_repeat(12345, 3) |
14. +-------------------------------+------------------------+
15. | [12345, 12345, 12345]         | [12345, 12345, 12345]  |
16. +-------------------------------+------------------------+
17. 1 row in set (0.01 sec)

19. mysql> select array_with_constant(3, null), array_repeat(null, 3);
20. +------------------------------+-----------------------+
21. | array_with_constant(3, NULL) | array_repeat(NULL, 3) |
22. +------------------------------+-----------------------+
23. | [NULL, NULL, NULL]           |  [NULL, NULL, NULL]   |
24. +------------------------------+-----------------------+
25. 1 row in set (0.01 sec)

27. mysql> select array_with_constant(null, 3), array_repeat(3, null);
28. +------------------------------+-----------------------+
29. | array_with_constant(NULL, 3) | array_repeat(3, NULL) |
30. +------------------------------+-----------------------+
31. | []                           | []                    |
32. +------------------------------+-----------------------+
33. 1 row in set (0.01 sec)

keywords

ARRAY,WITH_CONSTANT,ARRAY_WITH_CONSTANT,ARRAY_REPEAT