关联时想对关联表数据筛选时：
MySQL查询:

SELECT *  FROM A
LEFT JOIN B
ON A.B_id = B.id AND B.condition = $condition

ORM模型查询使用with():

Model::with(['table_name' => function ($query) use ($condition) {
            $query->where( "condition", $condition)
                        }])->get();)