Variable Relationships like timestamp or other ID

[SomniVertix]

Is there a way to create a relationship like a timestamp relationship with the gogm library? My use case isn't specifically timestamp, but a custom ID. For example, having a relationship between a repository and dependency, but in the relationship name, depicting which environment (dev, qa, uat, prod) has that dependency

[nikitawootten]

GoGM supports edges with additional properties ("special" edges). Special edges work a little different from regular relationships though. Take a look at the example from the ReadMe as an example:

//structs for the example (can also be found in decoder_test.go)
type VertexA struct {
	// provides required node fields
	gogm.BaseNode

    TestField         string                `gogm:"name=test_field"`
	TestTypeDefString tdString          `gogm:"name=test_type_def_string"`
	TestTypeDefInt    tdInt             `gogm:"name=test_type_def_int"`
	MapProperty       map[string]string `gogm:"name=map_property;properties"`
	SliceProperty     []string          `gogm:"name=slice_property;properties"`
    SingleA           *VertexB          `gogm:"direction=incoming;relationship=test_rel"`
	ManyA             []*VertexB        `gogm:"direction=incoming;relationship=testm2o"`
	MultiA            []*VertexB        `gogm:"direction=incoming;relationship=multib"`
	SingleSpecA       *EdgeC            `gogm:"direction=outgoing;relationship=special_single"`
	MultiSpecA        []*EdgeC          `gogm:"direction=outgoing;relationship=special_multi"`
}

type VertexB struct {
	// provides required node fields
	gogm.BaseNode

	TestField  string     `gogm:"name=test_field"`
	TestTime   time.Time  `gogm:"name=test_time"`
	Single     *VertexA   `gogm:"direction=outgoing;relationship=test_rel"`
	ManyB      *VertexA   `gogm:"direction=outgoing;relationship=testm2o"`
	Multi      []*VertexA `gogm:"direction=outgoing;relationship=multib"`
	SingleSpec *EdgeC     `gogm:"direction=incoming;relationship=special_single"`
	MultiSpec  []*EdgeC   `gogm:"direction=incoming;relationship=special_multi"`
}

type EdgeC struct {
	// provides required node fields
	gogm.BaseNode

	Start *VertexA
	End   *VertexB
	Test  string `gogm:"name=test"`
}

func (e *EdgeC) GetStartNode() interface{} {
    return e.Start
}

func (e *EdgeC) GetStartNodeType() reflect.Type {
    return reflect.TypeOf(&VertexA{})
}

func (e *EdgeC) GetEndNode() interface{} {
    return e.End
}

func (e *EdgeC) GetEndNodeType() reflect.Type {
    return reflect.TypeOf(&VertexB{})
}

The above example has a special edge type EdgeC with a special string property test. Special edges are defined very similarly to regular nodes, even requiring that the struct inherits from gogm.BaseNode.

Currently, special edges have the additional requirement that they implement the special edge interface requiring the edge to implement the GetStartNode(), GetEndNode(), GetStartNodeType(), and GetEndNodeType() methods. This will eventually be replaced and deprecated with something a little less verbose.

Other then that hurdle, special relationships can be treated almost exactly like a regular node.

[SomniVertix]

So, I was thinking more like how to say that the relationship name includes a timestamp. Ex:

type VertexB struct {
	// provides required node fields
	gogm.BaseNode

	Single     *VertexA   `gogm:"direction=outgoing;relationship=TOUCHES_VERTA_AT_TIME_{dd.mm.yyyy}"`
}

This kind of follows some of the neo4j examples like the modeling flights in neo4j.

[nikitawootten]

Ah so instead of a special edge with data inside of it, you mean storing data in the label of the edge itself?

Unfortunately that would be pretty difficult to write queries for (impossible to write queries that use parameters that is) and I'm sure that would cause scaling issues for your database.

Could you link the example your referring to? I'm definitely curious :).

[SomniVertix]

okay, so, now that I've had time to look at neo4j a bit more, I see how this should work. I shouldn't name the relationship based off of the time, i should just add a field in the relationship that states the timestamp lol.

Sorry it took forever for me to realize