Calculate Min Date

Neo4j Graph Platform Cypher
1

Hi Everyone,

Again I am stuck at a step, here I want to find the name of the nodes where the date is the least with a particular condition:

image
image1451×1024 26.8 KB

this has multiple capacity nodes and I need to find out the least date nodes where Available capacity < Required capacity

I have written this query but this is returning all the nodes with their dates

match (b:Capacity)
where b.Available_Capacity<b.Required_Capacity 
with b,min(b.Date) as date
return b.name order by date ;

Another method using apoc is returning me the nodes in the graph format but I just want the name property of this node:

match (b:Capacity) 
where b.Available_Capacity<b.Required_Capacity 
WITH apoc.agg.minItems(b, b.Date) AS minItems
return  minItems

In this graph the output should be nodes A and B, assuming the where condition is satisfied.

Can someone pls suggest what is the best way to return name property of these nodes?

Thank You :slight_smile:

2 
Try this:
match (b:Capacity)
where b.Available_Capacity<b.Required_Capacity 
with b.name as name, b.Date as date
return name order by date
3

Hi ameya,

I tried this but it is returning all the node names with dates in ascending order. But I want that the nodes with the least date should be returned. That is node A with date 08-2021 and node B with date 08-2021.

Hence, I just want the name of the nodes where the date is minimum. In this example there are 2 such nodes but in my graph DB there can be any number of nodes where date is minimum.

Thanks,
Pragya

4 
Try this:

match (b:Capacity)
where b.Available_Capacity<b.Required_Capacity 
with min(b.date) as dt
match (a:Capacity) 
where a.Available_Capacity<a.Required_Capacity
where a.date = dt
return a.name
5

Thanks this worked :slight_smile:

6

You almost have it with this query, all you need to do is project, from the minItems structure, the elements of it you want. You could use RETURN [node IN minItems.items | node.name] as names, minItems.value as minDate to get the list of names associated with nodes that had the given minimum data value.