[CASSANDRA-8079] Query specific keys from the map type

• Type: Improvement
• Status: Resolved
• Priority: Normal
• Resolution: Duplicate
• Assignee: Unassigned
• Reporter: Frank-Robert Kline
• Created: 08/Oct/14 01:33
• Updated: 16/Apr/19 09:31
• Resolved: 08/Oct/14 07:07

Description

Using the map type, we can set specific key+value pairs individually:

UPDATE users SET todo['first'] = 'value1'  WHERE user_id = 'frodo';
UPDATE users SET todo['second'] = 'value2'  WHERE user_id = 'frodo';

There is no analogous way to request specific properties from a map by key. This is significant when a map could potentially store many properties from which only a subset is required.

Ideally, the query syntax would reflect the mutation syntax, as in:

SELECT todo['first'], todo['second'] FROM users WHERE user_id = 'frodo';

Issue Links

• duplicates: CASSANDRA-7396 Allow selecting Map values and Set elements