Gremlin upsert on a vertex but preventing updates on a particular property on a vertex during upsert
Hi, Following is an upsert query on a vertex with label 'stvertex' and I am required to initialize and default the 'flagProp' to 0 only during creation of this vertex but during update I am required to prevent any update only on 'flagProp' while rest of the property should update, below is one of the approach I took: g.V(id).fold().coalesce(unfold(), __.addV(‘stvertex’)
.property(T.id, id).property(Cardinality.single, flagProp,0))
.property(Cardinality.single, name, nameValue)
.property(Cardinality.single, station, stationValue)
.property(Cardinality.single, base, baseValue).next() The above query only works for creation of new vertex I am looking for some help to write the correct query which works for update as well
Solution:Jump to solution
Hi Salman,
Better to use
mergeV step.
You may set flagProp in onCreate option, and create/update all other properties in both onCreate and onMatch, something like
`gremlin> g.mergeV([(T.label):'stvertex'])....3 Replies
Solution
Hi Salman,
Better to use
mergeV step.
You may set flagProp in onCreate option, and create/update all other properties in both onCreate and onMatch, something like
gremlin> g.mergeV([(T.label):'stvertex']).
......1> option(Merge.onCreate,[flagProp:0, name:'test1']).
......2> option(Merge.onMatch,[name:'test2'])
==>v[17]
gremlin> g.V(17).elementMap()
==>[id:17,label:stvertex,name:test1,flagProp:0]
gremlin> g.mergeV([(T.label):'stvertex']).
......1> option(Merge.onCreate,[flagProp:0, name:'test1']).
......2> option(Merge.onMatch,[name:'test2'])
==>v[17]
gremlin> g.V(17).elementMap()
==>[id:17,label:stvertex,name:test2,flagProp:0]Also just to throw in the docs link on MergeV, there are some additional examples and explanations of the step there https://tinkerpop.apache.org/docs/current/reference/#mergevertex-step
Thank you Velentyn and Yang for the suggestion I will try it out