struct_element
struct_element
struct_element
description
Function allows getting a field from a struct.
Syntax
struct_element(struct, n/s)
Arguments
struct - The input struct column. If null, null will be returned.
n - The position of field，starting from 1，only supports constants.
s - The name of field，only supports constants.
Returned value
Returns the specified field column, of any type.
notice
Only supported in vectorized engine
example
mysql> select struct_element(named_struct('f1', 1, 'f2', 'a'), 'f2');
+--------------------------------------------------------+
| struct_element(named_struct('f1', 1, 'f2', 'a'), 'f2') |
+--------------------------------------------------------+
| a |
+--------------------------------------------------------+
1 row in set (0.03 sec)
mysql> select struct_element(named_struct('f1', 1, 'f2', 'a'), 1);
+-----------------------------------------------------+
| struct_element(named_struct('f1', 1, 'f2', 'a'), 1) |
+-----------------------------------------------------+
| 1 |
+-----------------------------------------------------+
1 row in set (0.02 sec)
mysql> select struct_col, struct_element(struct_col, 'f1') from test_struct;
+-------------------------------------------------+-------------------------------------+
| struct_col | struct_element(`struct_col `, 'f1') |
+-------------------------------------------------+-------------------------------------+
| {1, 2, 3, 4, 5} | 1 |
| {1, 1000, 10000000, 100000000000, 100000000000} | 1 |
| {5, 4, 3, 2, 1} | 5 |
| NULL | NULL |
| {1, NULL, 3, NULL, 5} | 1 |
+-------------------------------------------------+-------------------------------------+
9 rows in set (0.01 sec)
keywords
STRUCT, ELEMENT, STRUCT_ELEMENT
