Question

我正在使用车辆历史记录数据库和 OrientDb Studio 2.2.8 ，我想要预览由automobile制作的Kia类的所有记录}。

数据库的架构如下所示：

(Automobile) --isModel--> (Model) --isMake--> (Make)

其中Automobile，Model和Make是顶点，isModel和isMake是边缘类型。

我想使用遍历语句来返回我从此命令获得的等效结果集：

Select expand(in('isMake').in('isModel')) from Make where name = "Kia"

其结果是......

+----+--------+---------+---------+---------+---------+---------+---------+---------+---------+---------+
|#   |@RID    |@CLASS   |color    |convertib|out_isMod|trailerHi|emissions|safety   |out_Purch|VIN      |
+----+--------+---------+---------+---------+---------+---------+---------+---------+---------+---------+
|0   |#17:1441|Automo...|White    |true     |[#24:1...|false    |2016-0...|2014-0...|[#23:5...|840CDC...|
|1   |#17:1576|Automo...|Maroon   |true     |[#24:1...|false    |2010-0...|2004-0...|[#23:5...|E71761...|
|2   |#17:1503|Automo...|Dark Gray|true     |[#24:1...|false    |2009-0...|2016-1...|[#23:5...|FAEB6F...|
+----+--------+---------+---------+---------+---------+---------+---------+---------+---------+---------+

我试过这个：

Select
  from (traverse in from Make while $depth <= 2)
  where name = "Kia"

我刚刚返回一条记录，并且它不像我预期的那样属于汽车类。它来自Make。

+----+-------+------+----+-------------------------------------+----------------------------+
|#   |@RID   |@CLASS|name|in_isMake                            |out_Sold                    |
+----+-------+------+----+-------------------------------------+----------------------------+
|0   |#15:612|Make  |Kia |[#25:1767,#25:2036,#25:2067,#25:2131]|[#22:5153,#22:5383,#22:5655]|
+----+-------+------+----+-------------------------------------+----------------------------+

基本上，我想使用从Make开始的Traverse在数据库中投射三辆起亚汽车。

Answer 1

你能试试吗？

SELECT FROM (TRAVERSE in() 
FROM (SELECT FROM Make where name='Kia')) 
WHERE @class='Automobile'

使用Traverse来预测OrientDB中的记录

1 个答案: