I am trying to insert json data in to a table with json check constraint. The non-ascii characters are unicode escaped. This fails in cases where the string in the json data has unicode points in non-BMP plane, e.g U+1F449. Error: ERROR 4025 (23000): CONSTRAINT `js` failed for `t`.`t` The same json works if the unicode characters are encoded in utf-8 and not escaped. I think I can confirm that this is a json validation error with json_valid. MariaDB [t]> show create table t; +-------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ | Table | Create Table | +-------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ | t | CREATE TABLE `t` ( `id` int(11) NOT NULL AUTO_INCREMENT, `js` longtext CHARACTER SET utf8mb4 COLLATE utf8mb4_bin DEFAULT NULL CHECK (json_valid(`js`)), PRIMARY KEY (`id`) ) ENGINE=MyISAM AUTO_INCREMENT=19 DEFAULT CHARSET=utf8mb4 | +-------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ 1 row in set (0.00 sec) MariaDB [t]> select json_valid('{"test": "\\ud83d\\ude0b"}'); +------------------------------------------+ | json_valid('{"test": "\\ud83d\\udc49"}') | +------------------------------------------+ | 0 | +------------------------------------------+ 1 row in set (0.00 sec) This is on Maria 10.3 MariaDB [t]> select version(); +----------------+ | version() | +----------------+ | 10.3.8-MariaDB | +----------------+ So, my questions, are unicode escaped strings in json supported? Is this a bug or a limitation? I have searched for this issue and have failed to come up with anything. Thanks, Manoj