postgreSQL解析json字符串字段

process_issue 表中字段’_app’为json字符串类型

SELECT cast(_app as jsonb)->>'updated' app_updatetime,  _id AS id, _id AS title, _full_text AS CONTENT, _app AS app, _files AS files,info AS info FROM
process_issue WHERE _files != '[ ]'
and cast(_app as jsonb)->>'updated' > '2020-09-06 07:01:42'