element_at
element_at
element_at
description
Syntax
T element_at(ARRAY<T> arr, BIGINT position)
T arr[position]
Returns an element of an array located at the input position. If there is no element at the position, return NULL.
position is 1-based and support negative number.
notice
Only supported in vectorized engine
example
positive position example:
mysql> set enable_vectorized_engine=true;
mysql> SELECT id,c_array,element_at(c_array, 5) FROM `array_test`;
+------+-----------------+--------------------------+
| id | c_array | element_at(`c_array`, 5) |
+------+-----------------+--------------------------+
| 1 | [1, 2, 3, 4, 5] | 5 |
| 2 | [6, 7, 8] | NULL |
| 3 | [] | NULL |
| 4 | NULL | NULL |
+------+-----------------+--------------------------+
negative position example:
mysql> set enable_vectorized_engine=true;
mysql> SELECT id,c_array,c_array[-2] FROM `array_test`;
+------+-----------------+----------------------------------+
| id | c_array | %element_extract%(`c_array`, -2) |
+------+-----------------+----------------------------------+
| 1 | [1, 2, 3, 4, 5] | 4 |
| 2 | [6, 7, 8] | 7 |
| 3 | [] | NULL |
| 4 | NULL | NULL |
+------+-----------------+----------------------------------+
keywords
ELEMENT_AT, SUBSCRIPT
