Neo4j.NET - Practical Neo4j - page 110

Products Purchased by Friends and Matches User's Tags
In this next instance, we want to determine products that have been purchased by friends but also have tags that are
used by the current user. The result of the query is shown in Figure 7-16 .
Figure 7-16. Products Purchased by Friends and Matches User's Tags
Using friendsPurchaseTagSimilarity in PurchaseService , shown in Listing 7-55, the application provides the
userId to the query and uses the FOLLOWS , MADE , and CONTAINS relationships to return products purchases by users
being followed. The subsequent MATCH statement takes the USES and HAS directed relationship types to determine
the TAG connections the resulting products and the current user have in common.
Listing 7-55. The friendsPurchaseTagSimilarity Method in PurchaseService
public List<MappedProductUserPurchase> friendsPurchaseTagSimilarity(string userId)
{
return _graphClient.Cypher
.Match("(u:User { userId : {userId} } )-[:FOLLOWS]-(f)-[:MADE]->()-[:CONTAINS]->p")
.WithParam("userId", userId)
.With("u,p,f")
.Match("u-[:USES]->(t)<-[:HAS]-p")
.Return(() => Return.As<MappedProductUserPurchase>("{productId:p.productId,title:p.
title," +
"fullname:collect(f.firstname + ' ' + f.lastname),wordPhrase:t.wordPhrase,cfriends:
count(f)}"))
.OrderByDescending("count(f)")
.Results.ToList();
}