JSON_
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Computes the length of a JSON map or array.
JSON_LENGTH(json)
Arguments
-
json: a valid JSON array or map.
Return Value
-
the length as an integer.
-
SQL NULL if json is not a valid JSON array or map.
Examples
SELECT JSON_LENGTH('true');
+---------------------+
| JSON_LENGTH('true') |
+---------------------+
| NULL |
+---------------------+SELECT JSON_LENGTH('[1,2,3]');
+------------------------+
| JSON_LENGTH('[1,2,3]') |
+------------------------+
| 3 |
+------------------------+SELECT JSON_LENGTH('{"alpha": 1, "beta": 2}');
+----------------------------------------+
| JSON_LENGTH('{"alpha": 1, "beta": 2}') |
+----------------------------------------+
| 2 |
+----------------------------------------+Note
A JSON or Javascript null value is distinct from SQL NULL.
Last modified: April 4, 2023