Howdy,
I'm using Neo4j 3.5.6 in a Node.js app. I have a data set of existing nodes containing a b:Beer that can have 1 or more relationships to a h:Hop. I am trying to write a query that allows for sometimes having only 1 hop relating to 1 beer, or sometimes having 7+ hops relating to 1 beer.
I have been trying variations of the following query, but nothing is working...
Match (b:Beer {name:{beernameParam}})
Optional Match (h:Hop {name:{hopnameParam}})
With collect(h.name) as hop,b
Unwind hop as hops
Create (hops)<-[r:BREWED_WITH]-(b)
Return hops,b
My hope is that from my form input option of </>select multiple</> hops that I coud sometimes add only 1 relationship or sometimes many relationships.
Here is my ejs form code...
<form method="post" action="/beerhop/add">
<label>Beer Name</label>
<select class="form-control" type="text" name="beername">
<% beer.forEach(function(beer){ %>
<option><%= beer.name %></option>
<% }) %>
</select>
<label>Hop Name</label>
<select class="form-control" type="text" name="hopname" multiple>
<% hop.forEach(function(hop){ %>
<option><%= hop.name %></option>
<% }) %>
</select>
<input class="button" type="submit" value="Submit">
</form>
Here is my server-side app.post...
app.post('/beerhop/add',async (req, res) => {
const {beername, hopname} = req.body;
try {
const result = await session.run(`Match (b:Beer {name:{beernameParam}})
Optional Match (h:Hop {name:{hopnameParam}})
With collect(h) as hops, b
Unwind hops as hop
Create (hop)<-[r:BREWED_WITH]-(b)
Return hop,b`,
{hopnameParam:hopname, beernameParam:beername});
if (result) {
res.redirect('/');
console.log(hopname);
session.close()
}
} catch (e) {
console.log("Something went wrong", e)
};
});
What am I doing wrong in my cypher query to create an optional many hops to 1 beer relationship?
Thanks,
Ka
