mongo sql 说明 db.users.find() select * from users 从user表中查询所有数据 db.users.find({“username” : “joe”, “age” : 27}) select * from users where “username” = “joe” and age = 27 查找username = joe且age = 27的人 db.users.find({}, {“username” : 1, “email” : 1}) sele…