JSON.MERGE

Merge a given JSON value into matching paths. Consequently, JSON values at matching paths are updated, deleted, or expanded with new children.

This command complies with RFC7396 Json Merge Patch

Examples

Required arguments

<details open><summary><code>key</code></summary>

is the key to merge into.

</details> <details open><summary><code>path</code></summary>

specifies the JSONPath. For non-existing keys the path must be $. For existing keys, for each matched path, the value that matches the path is merged with the JSON value. For existing keys, when the path exists, except for the last element, a new child is added with the JSON value.

</details> <details open><summary><code>value</code></summary>

is the JSON value to merge with at the specified path. Merging is done according to the following rules per JSON value in the value argument while considering the corresponding original value if it exists:

• merging an existing object key with a null value deletes the key
• merging an existing object key with non-null value updates the value
• merging a non-existing object key adds the key and value
• merging an existing array with any merged value, replaces the entire array with the value

</details>

Examples

JSON.MERGE provides four different behaviors to merge changes on a given key: create a non-existent path, update an existing path with a new value, delete an existing path, or replace an array with a new array

<details open> <summary><b>Create a non-existent path-value</b></summary>

{{< highlight bash >}} redis> JSON.SET doc $ '{"a":2}' OK redis> JSON.MERGE doc $.b '8' OK redis> JSON.GET doc $ "[{"a":2,"b":8}]" {{< / highlight >}}

</details> <details open> <summary><b>Replace an existing value</b></summary>

{{< highlight bash >}} redis> JSON.SET doc $ '{"a":2}' OK redis> JSON.MERGE doc $.a '3' OK redis> JSON.GET doc $ "[{"a":3}]" {{< / highlight >}}

</details> <details open> <summary><b>Delete an existing value</b></summary>

{{< highlight bash >}} redis> JSON.SET doc $ '{"a":2}' OK redis> JSON.MERGE doc $ '{"a":null}' OK redis> JSON.GET doc $ "[{}]" {{< / highlight >}}

</details> <details open> <summary><b>Replace an Array</b></summary>

{{< highlight bash >}} redis> JSON.SET doc $ '{"a":[2,4,6,8]}' OK redis> JSON.MERGE doc $.a '[10,12]' OK redis> JSON.GET doc $ "[{"a":[10,12]}]" {{< / highlight >}}

</details> <details open> <summary><b>Merge changes in multi-paths</b></summary>

{{< highlight bash >}} redis> JSON.SET doc $ '{"f1": {"a":1}, "f2":{"a":2}}' OK redis> JSON.GET doc "{"f1":{"a":1},"f2":{"a":2}}" redis> JSON.MERGE doc $ '{"f1": null, "f2":{"a":3, "b":4}, "f3":[2,4,6]}' OK redis> JSON.GET doc "{"f2":{"a":3,"b":4},"f3":[2,4,6]}" {{< / highlight >}}

</details>

Redis Software and Redis Cloud compatibility

| Redis Software | Redis Cloud | <span style="min-width: 9em; display: table-cell">Notes</span> | |:----------------------|:-----------------|:------| | <span title="Supported">✅ Standard</span> <span title="Supported"><nobr>✅ Active-Active</nobr></span> | <span title="Supported">✅ Standard</span> <span title="Supported"><nobr>✅ Active-Active</nobr></span> | |

Return information

{{< multitabs id="json-merge-return-info" tab1="RESP2" tab2="RESP3" >}}

One of the following:

• [Simple string reply]({{< relref "/develop/reference/protocol-spec#simple-strings" >}}): OK if executed correctly.
• [Simple error reply]({{< relref "/develop/reference/protocol-spec#simple-errors" >}}): if the operation fails to set the new values.

-tab-sep-

One of the following:

• [Simple string reply]({{< relref "/develop/reference/protocol-spec#simple-strings" >}}): OK if executed correctly.
• [Simple error reply]({{< relref "/develop/reference/protocol-spec#simple-errors" >}}): if the operation fails to set the new values.

{{< /multitabs >}}

See also

[JSON.GET]({{< relref "commands/json.get/" >}}) | [JSON.MGET]({{< relref "commands/json.mget/" >}}) | [JSON.SET]({{< relref "commands/json.set/" >}}) | [JSON.MSET]({{< relref "commands/json.mset/" >}})

Related topics

• [RedisJSON]({{< relref "/develop/data-types/json/" >}})
• [Index and search JSON documents]({{< relref "/develop/ai/search-and-query/indexing/" >}})