[FLINK-32261] Add MAP_UNION support in SQL & Table API

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.18.0
• Fix Version/s: 1.20.0
• Component/s: Table SQL / Planner
• Labels: pull-request-available stale-assigned
• Assignee: Hanyu Zheng
• Reporter: Bonnie Varghese
• Created: 05/Jun/23 18:24
• Updated: 11/Mar/24 21:13
• Resolved: 11/Mar/24 21:13

Description

Description:

This is an implementation of MAP_UNION 

Returns a map created by merging two maps, 'map1' and 'map2'. This two maps should have same data structure. If there are overlapping keys, the value from 'map2' will overwrite the value from 'map1'. If any of maps are null, return null.

Syntax:

MAP_UNION(map1, map2)

Arguments:

• map1:The first map to be merged.
• map2:The second map to be merged.

Returns: A new map that contains the combined key-value pairs from map1 and map2. If there are any overlapping keys, the value from map2 will overwrite the value from map1.

Examples:

 Merging maps with unique keys:

 

map1 = ['a': 1, 'b': 2] map2 = ['c': 3, 'd': 4] 
map_union[map1, map2]  
Output: ['a': 1, 'b': 2, 'c': 3, 'd': 4]

 Merging maps with overlapping keys:

 
 

map1 = ['a': 1, 'b': 2] map2 = ['b': 3, 'c': 4] 
map_union[map1, map2] 
Output: ['a': 1, 'b': 3, 'c': 4]

See also:

prestodb: https://prestodb.io/docs/current/functions/aggregate.html

 

 

Issue Links

• links to: GitHub Pull Request #22842
• links to: GitHub Pull Request #22950