JSON_DEPTH

Discover JSON_DEPTH in MariaDB. This function returns the maximum depth of a JSON document, assigning a depth of 1 to scalars and empty structures, and higher values for nested data.

Syntax

JSON_DEPTH(json_doc)

Description

Returns the maximum depth of the given JSON document, or NULL if the argument is null. An error occurs if the argument is an invalid JSON document.

• Scalar values or empty arrays or objects have a depth of 1.

• Arrays with only scalar values and objects with only scalar values for all keys have depth of 1.

• In all other cases, the depth can be 2 or greater.

12.2

There is no maximum depth level — it's unlimited.

For more information, see this blog post.

< 12.2

Examples

SELECT JSON_DEPTH('[]'), JSON_DEPTH('true'), JSON_DEPTH('{}');
+------------------+--------------------+------------------+
| JSON_DEPTH('[]') | JSON_DEPTH('true') | JSON_DEPTH('{}') |
+------------------+--------------------+------------------+
|                1 |                  1 |                1 |
+------------------+--------------------+------------------+

SELECT JSON_DEPTH('[1, 2, 3]'), JSON_DEPTH('[[], {}, []]');
+-------------------------+----------------------------+
| JSON_DEPTH('[1, 2, 3]') | JSON_DEPTH('[[], {}, []]') |
+-------------------------+----------------------------+
|                       2 |                          2 |
+-------------------------+----------------------------+

SELECT JSON_DEPTH('[1, 2, [3, 4, 5, 6], 7]');
+---------------------------------------+
| JSON_DEPTH('[1, 2, [3, 4, 5, 6], 7]') |
+---------------------------------------+
|                                     3 |
+---------------------------------------+

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