Need help to frame a query

[rajidiloj]

Hi
I have a node class with student_name and class_name as attributes. How can I frame a query to find how many students belong to each class?
Thank you.

[dana_canzano]

not a lot to go upon here. but lets say

create (n:Student {id:1, name:'Emil'});
create (n:Student {id:2, name:'Jim'});
create (n:Student {id:3, name:'Philip'});

create (n:Class {id:1, name:'Math'});
create (n:Class {id:2, name:'History'});

match (n:Student {name:'Jim'}), (n2:Class {name:'Math'}) create (n)-[:ATTENDS]->(n2);
match (n:Student {name:'Jim'}), (n2:Class {name:'History'}) create (n)-[:ATTENDS]->(n2);
match (n:Student {name:'Emil'}), (n2:Class {name:'History'}) create (n)-[:ATTENDS]->(n2);
match (n:Student {name:'Philip'}), (n2:Class {name:'History'}) create (n)-[:ATTENDS]->(n2);

then

match (c:Class) return c.name, size  (   (c)<-[:ATTENDS]-() );

will report

Math   1
History 3

[rajidiloj]

Thank you so much for your help. But in my case both student_name and student_class are attributes of one node and so, there is no relationship (as you mentioned in your solution) for my node. Each student has (id, name, class) and I want to find how many students are enrolled for class1,class2, class3 etc. Hope you understand my question.

[dana_canzano]

what queries have you tried

match (n:Class) return n.class_name,count(n.student_name);

[rajidiloj]

Thank you so much. Got the result. 🙂

[ameyasoft]

Try this:

MATCH (a:Student) 
//to get student count.........
with distinct a.class as Class, count(distinct a.id) as Count
RETURN Class, Count order by Count desc 

//use this to get student ids as an array
with distinct a.class as Class, collect(a.id) as ids
RETURN Class, ids, size(ids) as Count

[rajidiloj]

This also worked. Great! Thank you so much 🙂

[clem]

You might want to rethink your schema....

What you describing kind of defeats to purpose of a Graph DB.