2015-04-30 32 views
2

假设我打算定义OrientDB称为MYE新边缘种类和我有A和B为以下几点:强制边缘连接两个不同的顶点类

CREATE CLASS A EXTENDS V 
CREATE CLASS B EXTENDS V 
CREATE CLASS myE EXTENDS E 

我可以强制执行的一种原理约束将myE记录源和目标限制为A和B.换句话说,我希望orientDB限制myE记录只将A连接到B:当它的源和目标不是A和B时,它会阻止向myE添加记录?

例如,如果我有另一个顶点类说C:

CREATE CLASS C EXTENDS V 

,#10:3和11:4分别在C和B的记录,分别发出以下命令导致错误?

CREATE MyE FROM #10:3 TO #11:4 

回答

3
create class A extends V 
create class B extends V 
create class myE extends E 

create property myE.out LINK A 
create property myE.in LINK B 

create vertex A 
create vertex B 

create edge myE from (select from A) to (select from B) 
// works 

create class C extends V 
create vertex C 

create edge myE from (select from C) to (select from B) 
// does not work 

this

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