ARRAY_POSITION
array_position
Since Version 2.0.0查找数组中指定元素第一次出现的位置索引（从1开始）。函数会从左到右遍历数组，找到第一个匹配的元素并返回其位置索引。
array_position(ARRAY<T> arr, T element)
arr
：ARRAY
element
：T 类型，要查找的元素
T 支持的类型：
返回值
返回类型：BIGINT
返回值含义：
使用说明：
查询示例：
查找字符串在数组中的位置：
SELECT array_position(['apple', 'banana', 'cherry', 'apple'], 'apple');
+-----------------------------------------------------------------+
| array_position(['apple', 'banana', 'cherry', 'apple'], 'apple') |
+-----------------------------------------------------------------+
| 1 |
+-----------------------------------------------------------------+
查找浮点数在数组中的位置：
SELECT array_position([1.1, 2.2, 3.3, 4.4, 5.5], 3.3);
+------------------------------------------------+
| array_position([1.1, 2.2, 3.3, 4.4, 5.5], 3.3) |
+------------------------------------------------+
| 3 |
+------------------------------------------------+
查找不存在的元素：
SELECT array_position([1, 2, 3, 4, 5], 10);
+-------------------------------------+
| array_position([1, 2, 3, 4, 5], 10) |
+-------------------------------------+
| 0 |
+-------------------------------------+
查找 null 元素：
| array_position([1, null, 3, null, 5], null) |
+---------------------------------------------+
| 2 |
+---------------------------------------------+
空数组返回 0：
SELECT array_position([], 1);
+-----------------------+
| array_position([], 1) |
+-----------------------+
| 0 |
+-----------------------+
输入数组是 NULL，返回为NULL
SELECT array_position(NULL, 1);
+-------------------------+
| array_position(NULL, 1) |
+-------------------------+
| NULL |
+-------------------------+
日期类型查找：
SELECT array_position(cast(['2023-01-01', '2022-12-31', '2023-06-15'] as array<datetime>), '2023-01-01');
+---------------------------------------------------------------------------------------------------+
| array_position(cast(['2023-01-01', '2022-12-31', '2023-06-15'] as array<datetime>), '2023-01-01') |
+---------------------------------------------------------------------------------------------------+
| 1 |
+---------------------------------------------------------------------------------------------------+
IP 地址查找：
SELECT array_position(CAST(['192.168.1.1', '192.168.1.2', '192.168.1.3'] AS ARRAY<IPV4>), '192.168.1.2');
+---------------------------------------------------------------------------------------------------+
| array_position(CAST(['192.168.1.1', '192.168.1.2', '192.168.1.3'] AS ARRAY<IPV4>), '192.168.1.2') |
+---------------------------------------------------------------------------------------------------+
| 2 |
+---------------------------------------------------------------------------------------------------+
SELECT array_position(CAST(['2001:db8::1', '2001:db8::2', '2001:db8::0'] AS ARRAY<IPV6>), '2001:db8::0');
+---------------------------------------------------------------------------------------------------+
| array_position(CAST(['2001:db8::1', '2001:db8::2', '2001:db8::0'] AS ARRAY<IPV6>), '2001:db8::0') |
+---------------------------------------------------------------------------------------------------+
| 3 |
+---------------------------------------------------------------------------------------------------+
复杂类型示例：
嵌套数组类型不支持，报错：
SELECT array_position([[1,2], [3,4], [5,6]], [3,4]);
ERROR 1105 (HY000): errCode = 2, detailMessage = array_position does not support type ARRAY<ARRAY<TINYINT>>, expression is array_position([[1, 2], [3, 4], [5, 6]])
map 类型查找：
SELECT array_position([{'k':1}, {'k':2}, {'k':3}], {'k':2});
ERROR 1105 (HY000): errCode = 2, detailMessage = array_position does not support type ARRAY<MAP<VARCHAR(1),TINYINT>>, expression is array_position([map('k', 1), map('k', 2), map('k', 3)])
参数数量错误会报错：
SELECT array_position([1,2,3]);
ERROR 1105 (HY000): errCode = 2, detailMessage = Can not found function 'array_position' which has 1 arity. Candidate functions are: [array_position(Expression, Expression)]