building recommendation system using weight as relation

[hoseinmorshedy]

hello.

in my graph we have users that have 2 relation called "favorite" and "seen" with products and product have relation called has with some specification as colors(red blue...) , types(jeans....) and sizes (30...) 

so i make some query that when i wanna create favorite or seen relation , it makes a relation with that specific user and the specification of that product calling "weight" and set property for that called "score" and i wanna increase this score every time user that set product to favorite or just seeing that product for example when a user see the product score change to +10 and for favorite change to +20 and then we recommend products with specifications that have most score

my query is 

match (user:Users{m_id:""}),(m:Products{m_id:""})-[:HAS]->(a:Specifications)

    MERGE (user) -[:FAVORITE]-> (m)

    merge (user)-[:WEIGHT{score:0}]->(a)

and one more problem with this query is i dont wanna make new relation if i already have it i just wanna increase the score

[glilienfield]

You can use ‘on create’ clause with each merge to initialize each weight and use ‘on match’ to update each weight. 

[hoseinmorshedy]

hi again and tnx for helping.

do you mean something like this ?

match (user:Users{m_id:}),(m:Products{m_id:"})-[:HAS]->(a:Specifications)

MERGE (user) -[:FAVORITE]-> (m)

on create MERGE (user)-[:WEIGHT{score:10}]->(a)

i think after on create we should use SET

and one more question 

how should i check that if i already created that relation , update weight

[glilienfield · Accepted solution]

Something like the following: 

match (user:Users{m_id:""})
match (m:Products{m_id:""})-[:HAS]->(a:Specifications)
merge (user) -[f:FAVORITE]-> (m)
on create set f.score = 0
on match set f.score = f.score + 10
merge (user)-[w:WEIGHT]->(a)
on create set w.score = 0
on match set w.score = w.score + 20

[hoseinmorshedy]

really help full tnx sir really appreciate

[hoseinmorshedy]

hello again i have one more problem😅

im adding a property for specifications that name of them is "color" "type" "size" and its called "ratio" the reason is i want to give them some coefficient to give recommend most based on types then colors and so on

so now i wanna get that ratio and multiply with weight that has relation with that sub specification

this is what i write for give recommend but couldnt save ratio in other variable and then multiply with weight 

match (u:Users{m_id:"62aad7f641f29f97fbdead54"})-[w:WEIGHT]->(a:Specifications)

match (u)-[w]->(a)<-[:HAS]-(prod:Products)

match (a)-[:is]->(b:Specifications)

where  b.name = "color" and w<i dont know how to select that relation> set sc = b.ratio* w

with u , prod ,collect(w.score)as scorelist, sum(w.score) as score ,sc

return u.name as user,prod.name as products ,scorelist, sc as test,score order by score desc

[hoseinmorshedy]

and one more thing how to update weight with that specific attribute 

is it even possible to have some weight relation and 1 property that the property has different value ?

and if its not possible what do you think we can do

tnx for your time