# JSON\_MERGE

## Syntax

```sql
JSON_MERGE(json_doc, json_doc[, json_doc] ...)
```

## Description

Merges the given JSON documents.

Returns the merged result, or `NULL` if any argument is `NULL`.

An error occurs if any of the arguments are not valid JSON documents.

{% hint style="warning" %}
`JSON_MERGE` is deprecated. [JSON\_MERGE\_PATCH](https://mariadb.com/docs/server/reference/sql-functions/special-functions/json-functions/json_merge_patch) is an RFC 7396-compliant replacement, and [JSON\_MERGE\_PRESERVE](https://mariadb.com/docs/server/reference/sql-functions/special-functions/json-functions/json_merge_preserve) is a synonym.
{% endhint %}

## Example

```sql
SET @json1 = '[1, 2]';
SET @json2 = '[3, 4]';

SELECT JSON_MERGE(@json1,@json2);
+---------------------------+
| JSON_MERGE(@json1,@json2) |
+---------------------------+
| [1, 2, 3, 4]              |
+---------------------------+
```

## See Also

* [JSON\_MERGE\_PATCH](https://mariadb.com/docs/server/reference/sql-functions/special-functions/json-functions/json_merge_patch)
* [JSON\_MERGE\_PRESERVE](https://mariadb.com/docs/server/reference/sql-functions/special-functions/json-functions/json_merge_preserve)

<sub>*This page is licensed: CC BY-SA / Gnu FDL*</sub>

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