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CREATE table js (val varchar(1000))
INSERT INTO js VALUEs ('[{"confidence":99,"iso_code":"NJ","geoname_id":5101760,"names":{"en":"New Jersey","es":"Nueva Jersey","fr":"New Jersey","ja":"\u30cb\u30e5\u30fc\u30b8\u30e3\u30fc\u30b8\u30fc\u5dde","pt-BR":"Nova J\u00e9rsia","ru":"\u041d\u044c\u044e-\u0414\u0436\u0435\u0440\u0441\u0438","zh-CN":"\u65b0\u6cfd\u897f\u5dde"}}]
')
INSERT INTO js VALUEs ('')
SELECT * FROM js WHERE JSON_EXTRACT(val, "$[0].iso_code") = 'NJ'
SELECT
JSON_EXTRACT(val, "$[0].iso_code") from js