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JSON_LENGTH

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 |
+----------------------------------------+

Notice

A JSON or Javascript null value is distinct from SQL NULL.