Cannot construct date time from: NO_VALUE (Failure when processing file

[hi_joshi]

Hello there,
I am loading the data from a sample CSV into Employee. The CSV has 2 columns - birthdate and hiredate. The code is like this -

load csv with headers from 'file:///northwind/employees2.csv' as row
merge(c:Country {country : row.country})
merge(e:Employee {
employeeId:toInteger(row.employeeID)
,firstName : row.firstName
,birthDate : date(datetime({epochmillis:apoc.date.parse(row.birthdate, 'ms', 'yyyy-MM-dd')}))
,hireDate : date(datetime({epochmillis:apoc.date.parse(row.hiredate, 'ms', 'yyyy-MM-dd')}))
})
create (e) - [:HAS_COUNTRY {countryName:c.country}] -> (c);

Getting following error -

Cannot construct date time from: NO_VALUE (Failure when processing file '/C:/neo4j423/import/northwind/employees.csv' on line 2.)

I tried with just 1 row in the csv. birthdate and hiredate both are available.
If I try with a hardcoded value like '2001-01-01', the code works just fine.

Any ideas what could be wrong?

Thanks

Manoj Joshi

[asharpe]

I have the same issue. Did you end up solving it?
It seems that the datetime() function requires a hardcoded timestamp value rather than a variable or alias

[ameyasoft]

Please post the date value as in your .csv file so that I can suggest a solution

[asharpe]

@ameyasoft I'm not sure about OP's value, but mine is 1609283699032, and the query giving me the

Cannot construct date time from: NO_VALUE error is the one below

match (n:MyNode) 
with date(datetime({epochmillis: n.timestamp})) as r 
return r

where n.timestamp is the value 1609283699032

[ameyasoft]

asharpe:

1609283699032

.csv file stores all values as strings. While importing, one needs to use toInteger function and that stores the property value as integer. Here is the workaround sample:

with '1609283699032' as tme
with date(datetime({epochmillis: toInteger(tme)})) as r
return r

Result: "2020-12-29"

[asharpe]

@ameyasoft thank you!

For anyone who reads this in the future:
After trying out ameyasoft's solution, I discovered that passing in a string timestamp could also produce this different error: Cannot construct date time from: String("1609283699032") , which is more informative than the first error I got.
After that, I also realized that my error was coming from me reading in null values for n.timestamp, so I just added a WHERE n.timestamp IS NOT NULL, and it fixed the problem