JSON.MERGE

Syntax

  1. JSON.MERGE key path value

Time complexity: O(M+N) where M is the size of the original json object located at key, and N is the size of the value merged into it.

ACL categories: @json

The JSON.MERGE command merges a provided JSON value into matching paths within the existing JSON object at the specified key. This operation can result in updates, deletions, or the creation of new children within the target object.

Merge Behavior:

  • Matching paths in the original object are updated with the corresponding values from the provided JSON.
  • Non-existent paths in the original object are created as new children with the values from the provided JSON.
  • Existing paths can be deleted if the corresponding value in the provided JSON is null.

Standard Compliance:

This command adheres to the specifications outlined in RFC7396.

Return

JSON.MERGE returns “OK” in case of success, or error otherwise.

Examples

Update the existing document:

  1. dragonfly> JSON.SET key $ '{"a":1, "b" : 2}'
  2. OK
  3. dragonfly> JSON.MERGE key $ '{"b" : 3}'
  4. OK
  5. dragonfly> JSON.GET key $
  6. "[{\"a\":1,\"b\":3}]"
  8. dragonfly> JSON.MERGE key $.b 4
  9. OK
  10. dragonfly> JSON.GET key $
  11. "[{\"a\":1,\"b\":4}]"

Create a new path or value:

  1. dragonfly> JSON.MERGE new $ '{"b" : 3}'
  2. OK
  3. dragonfly> JSON.GET new $
  4. "[{\"b\":3}]"
  6. dragonfly> JSON.MERGE new $ '{"c" : "another"}'
  7. dragonfly> JSON.GET new $
  8. "[{\"b\":3,\"c\":\"another\"}]"

Delete paths:

  1. dragonfly> JSON.SET key $ '{"one" : 1, "two": 2}'
  2. OK
  3. dragonfly> JSON.MERGE key $ '{"one" : null}'
  4. OK
  5. dragonfly> JSON.GET key $
  6. "[{\"two\":2}]"