CREATE DATABASE test;
use test;
CREATE TABLE student (
id int,
cur_process_userid json
);
INSERT INTO student VALUES (1, '[{"userid":9,"username":"wzx-9"},{"userid":30,"username":"wzx-30"}]');
INSERT INTO student VALUES (2, '[{"userid":20,"username":"wzx-20"}]');
SELECT * FROM student WHERE json_contains(cur_process_userid,json_object('userid',9))