array_size (size, cardinality)

SinceVersion 1.2.0

array_size (size, cardinality)

description

Syntax

1. BIGINT size(ARRAY<T> arr)
2. BIGINT array_size(ARRAY<T> arr)
3. BIGINT cardinality(ARRAY<T> arr)

返回数组中元素数量，如果输入数组为NULL，则返回NULL

notice

仅支持向量化引擎中使用

example

1. mysql> set enable_vectorized_engine=true;

3. mysql> select k1,k2,size(k2) from array_test;
4. +------+-----------+------------+
5. | k1   | k2        | size(`k2`) |
6. +------+-----------+------------+
7. |    1 | [1, 2, 3] |          3 |
8. |    2 | []        |          0 |
9. |    3 | NULL      |       NULL |
10. +------+-----------+------------+

12. mysql> select k1,k2,array_size(k2) from array_test;
13. +------+-----------+------------------+
14. | k1   | k2        | array_size(`k2`) |
15. +------+-----------+------------------+
16. |    1 | [1, 2, 3] |                3 |
17. |    2 | []        |                0 |
18. |    3 | NULL      |             NULL |
19. +------+-----------+------------------+

21. mysql> select k1,k2,cardinality(k2) from array_test;
22. +------+-----------+-------------------+
23. | k1   | k2        | cardinality(`k2`) |
24. +------+-----------+-------------------+
25. |    1 | [1, 2, 3] |                 3 |
26. |    2 | []        |                 0 |
27. |    3 | NULL      |              NULL |
28. +------+-----------+-------------------+

keywords

ARRAY_SIZE, SIZE, CARDINALITY