MAP

Description

Syntax

MAP<K, V> map(K key0, V value0, K key1, V value1, ..., K keyn, V valuen)

使用若干组键值对构造一个特定类型的 Map<K, V>

Example

mysql> select map(1, "100", 0.1, 2);
+---------------------------------------------------------------------------------------+
| map(cast(1 as DECIMALV3(2, 1)), '100', cast(0.1 as DECIMALV3(2, 1)), cast(2 as TEXT)) |
+---------------------------------------------------------------------------------------+
| {1.0:"100", 0.1:"2"}                                                                  |
+---------------------------------------------------------------------------------------+
1 row in set (0.16 sec)

mysql> select map(1, "100", 0.1, 2)[1];
+-------------------------------------------------------------------------------------------------------------------------------+
| element_at(map(cast(1 as DECIMALV3(2, 1)), '100', cast(0.1 as DECIMALV3(2, 1)), cast(2 as TEXT)), cast(1 as DECIMALV3(2, 1))) |
+-------------------------------------------------------------------------------------------------------------------------------+
| 100                                                                                                                           |
+-------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.16 sec)

Keywords

MAP