Linqpad 7 translates sql type of Date to .NET type of DateOnly -- which is fine.
But if the column is primary key or part of primary key, following exception will be thrown:
Thanks for reporting. This should be fixed in 7.2.2:https://www.linqpad.net/LINQPad7.aspx#beta
I'm still seeing this issue in v7.2.7.
Note, using the same query in LinqPad 6 works fine.
I'm seeing this in v7.3.9. Will try to install v6.x to see if that works.
This should now be fixed in 7.4.1. Let me know if it's still an issue.