thinkphp5.0 field and in conjunction with the problem

field field will not work with in the back, it will query the database in all fields;

field will not be screened in the field associated with the table in front

The solution replaced with join, field and join the order does not matter

* @param mixed $join 关联的表名

* @param mixed $condition 条件

* @param string $type JOIN类型

* @return $this

join($join, $condition = null, $type = 'INNER')