There are null values present in the column which was specified as 'not null'.

[y0m0]

Hi I am getting a weird error when trying to run some simple select SQL queries against a lakehouse table.

It shows unable to preview data

and if I explicitly run a select * query

I get this error:
There are null values present in the column which was specified as 'not null'.

But I know that's not true.

Here is the table definition from my Notebook.

The column causing trouble is _processedAt

If i run the select * query from a Notebook it works as expected.

and if I check for NULL values it doesn't return any rows as expected.

I experimented with changing the table definition and removing the NOT NULL constraint from the _processedAt column and the error disappear. But this is not a proper solution because I want to keep the constraint.

I suspect it's an issue on how the timestamp data type is converted to datetime2 in the SQL Analytics endpoint as stated here:
https://learn.microsoft.com/en-us/fabric/data-warehouse/data-types#autogenerated-data-types-in-the-s...

[Hello-Im-Aaron]

Hi @y0m0. I am running into the same issue with my timestamps. Works find in notebooks but fails in the warehouse and as a consequence dfg2's. Were you able to find a workaround?

[y0m0]

@Hello-Im-Aaronmy workaround was to remove the NOT NULL constraint from the timestamp columns in the CREATE TABLE query.
It's not ideal, but I have control over the pipeline so it's not a big issue.

[Hello-Im-Aaron]

@y0m0 it was fixed for me in the last day or two. Hopefully for you as well

[Hello-Im-Aaron]

Thanks. I've had a ticket open since Friday. I'll let you know what happens

[Anonymous]

Hi @y0m0 
Thanks for using Fabric Community and reporting this. Apologies for the issue you have been facing.
At this time, we are reaching out to the internal team to get some help on this. We will update you once we hear back from them.
Appreciate your patience.
Thanks.

[Anonymous]

Hi @y0m0 

Apologies for the issue you have been facing. 

I would request you to please go ahead with Microsoft support for this. Please raise a support ticket on this link: https://support.fabric.microsoft.com/en-US/support/.

Also once you have opened the support ticket , please do share the supportcase# here. 

Thanks

[Anonymous]

Hi @y0m0 
We haven’t heard from you on the last response and was just checking back to see if you got a chance to create a support ticket. If yes please do share the ticket number here.
Otherwise, will respond back with the more details and we will try to help.
Thanks

[Anonymous]

Hi @y0m0 
We haven’t heard from you on the last response and was just checking back to see if you got a chance to create a support ticket. If yes please do share the ticket number here.
Otherwise, will respond back with the more details and we will try to help.
Thanks