ARRAY_WITH_CONSTANT
array_with_constant
array_with_constant array_repeat
description
Syntax
ARRAY<T> array_with_constant(n, T)
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
mysql> set enable_vectorized_engine=true;
mysql> select array_with_constant(2, "hello"), array_repeat("hello", 2);
+---------------------------------+--------------------------+
| array_with_constant(2, 'hello') | array_repeat('hello', 2) |
+---------------------------------+--------------------------+
| ['hello', 'hello'] | ['hello', 'hello'] |
+---------------------------------+--------------------------+
1 row in set (0.04 sec)
mysql> select array_with_constant(3, 12345), array_repeat(12345, 3);
+-------------------------------+------------------------+
| array_with_constant(3, 12345) | array_repeat(12345, 3) |
+-------------------------------+------------------------+
| [12345, 12345, 12345] | [12345, 12345, 12345] |
+-------------------------------+------------------------+
1 row in set (0.01 sec)
mysql> select array_with_constant(3, null), array_repeat(null, 3);
+------------------------------+-----------------------+
| array_with_constant(3, NULL) | array_repeat(NULL, 3) |
+------------------------------+-----------------------+
| [NULL, NULL, NULL] | [NULL, NULL, NULL] |
+------------------------------+-----------------------+
1 row in set (0.01 sec)
mysql> select array_with_constant(null, 3), array_repeat(3, null);
+------------------------------+-----------------------+
| array_with_constant(NULL, 3) | array_repeat(3, NULL) |
+------------------------------+-----------------------+
| [] | [] |
+------------------------------+-----------------------+
1 row in set (0.01 sec)
keywords
ARRAY,WITH_CONSTANT,ARRAY_WITH_CONSTANT,ARRAY_REPEAT
