Support JSON.MERGE

[wangxinqgz]

Can you support JSON.MERGE, just like RedisJSON?

JSON.SET directly overwrites the subtree with the new value, but does not perform the Merge operation.

Now, Merge a JSON subtree, requiring:

1. JSON.GET,
2. Write code Merge
3. JSON.SET

But JSON.MERGE can do it .

Another important reason is that Redis JSON uses the RUST language and valkey-json uses the C++ language.

This makes valkey-json the best choice in scenarios where Rust is not the development language.

[sarthakaggarwal97]

@wangxinqgz would you please share the usecases of something like JSON.MERGE? It sounds definitely interesting.

[wangxinqgz]

1. Valkey save a json like : a.b.c

{
  "a":{
    "b":{
         "c": "c-value"
     }
  }
}

2. I want add json node a.b.d. to a.b, But I don't know whether a.b.c exists, the merge result like:

{
  "a":{
    "b":{
         "c": "c-value",
         "d": "d-value"
     }
  }
}

3. So need merge a.b.d to a.b to do it.

4. If json.set is used, it will overwrite a.b, causing a.b.c to be lost.

{
  "a":{
    "b":{
         "d": "d-value"
     }
  }
}

[roshkhatri]

Yeah it would work with get

127.0.0.1:6379> JSON.SET mydoc $ '{"a":{"b":{"c":"c-value"}}}'
OK
127.0.0.1:6379> JSON.GET mydoc .a
"{\"b\":{\"c\":\"c-value\"}}"
127.0.0.1:6379> JSON.GET mydoc .a.b.c
"\"c-value\""
127.0.0.1:6379> JSON.SET mydoc $.a.b.d '"d-value"'
OK
127.0.0.1:6379> JSON.GET mydoc .a.b
"{\"c\":\"c-value\",\"d\":\"d-value\"}"
127.0.0.1:6379> JSON.GET mydoc .a
"{\"b\":{\"c\":\"c-value\",\"d\":\"d-value\"}}"
127.0.0.1:6379> 

But this would not:

127.0.0.1:6379> JSON.SET mydoc $ '{"a":{"b":{"c":"c-value"}}}'
OK
127.0.0.1:6379> JSON.SET mydoc $ '{"a":{"b":{"d":"d-value"}}}'
OK
127.0.0.1:6379> JSON.GET mydoc .a.b
"{\"d\":\"d-value\"}"
127.0.0.1:6379> 

[patrickn2]

We need this please

[soloestoy]

we need this : )

[roshkhatri]

Looking at the ask for this feature, will be working on JSON.MERGE and open a PR.

[patrickn2]

Looking at the ask for this feature, will be working on JSON.MERGE and open a PR.

I just opened
#95

[roshkhatri]

Great! Thank you so much, will take a look once I am back