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array_size

array_size (size, cardinality)

SinceVersion 1.2.0

array_size (size, cardinality)

description

Syntax

BIGINT size(ARRAY<T> arr)
BIGINT array_size(ARRAY<T> arr)
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

mysql> set enable_vectorized_engine=true;

mysql> select k1,k2,size(k2) from array_test;
+------+-----------+------------+
| k1 | k2 | size(`k2`) |
+------+-----------+------------+
| 1 | [1, 2, 3] | 3 |
| 2 | [] | 0 |
| 3 | NULL | NULL |
+------+-----------+------------+

mysql> select k1,k2,array_size(k2) from array_test;
+------+-----------+------------------+
| k1 | k2 | array_size(`k2`) |
+------+-----------+------------------+
| 1 | [1, 2, 3] | 3 |
| 2 | [] | 0 |
| 3 | NULL | NULL |
+------+-----------+------------------+

mysql> select k1,k2,cardinality(k2) from array_test;
+------+-----------+-------------------+
| k1 | k2 | cardinality(`k2`) |
+------+-----------+-------------------+
| 1 | [1, 2, 3] | 3 |
| 2 | [] | 0 |
| 3 | NULL | NULL |
+------+-----------+-------------------+

keywords

ARRAY_SIZE, SIZE, CARDINALITY