MAP

Description

Constructs a Map<K, V> of a specific type using some set of key-value pairs

Syntax

MAP( <key1> , <value1> [, <key2>,<value2> ... ])

Parameters

Parameter	Description
<key>	Constructing the key of the map
<value>	Constructing the value of the map

Return Value

Returns a specific type Map<K, V> constructed from a number of key-value pairs

Example

select map(1, "100", 0.1, 2),map(1, "100", 0.1, 2)[1];

+-----------------------+--------------------------+
| map(1, "100", 0.1, 2) | map(1, "100", 0.1, 2)[1] |
+-----------------------+--------------------------+
| {1.0:"100", 0.1:"2"}  | 100                      |
+-----------------------+--------------------------+

• If there are duplicate keys, they will be deduplicated：

select map(1, 2, 2, 11, 1, 3);

+------------------------+
| map(1, 2, 2, 11, 1, 3) |
+------------------------+
| {2:11, 1:3}            |
+------------------------+

There are two sets of parameters with the key 1 (1, 2 and 1, 3), only 1, 3 is retained.