Great video! I have one question: Why if I do a query like this in one to many relationship doesn't throw exception in ef core but with linq to object throws: Suppose I have one object with many serial numbers, because the current serial number is only the last but the table is the historical too,and I want to filter what object has the serial number but only among the most recent of every object, so I did a query like this: Context.Objects.Include(o=> o.SerialNumbers.Where(s=> s.TypeId==2)).Where(s=> s.SerialNumbers.OrderByDescending(s=>s.Date).FirstOrDefault().Value == passed serial number). FirstOrDefault() I did an include with condition, but in the where clause I expected that the FirstOrDefault().Value throws exception where the FirstOrDefault () results null, but in ef core this doesn't happen. There is a explanation to this? Sorry for my english and my long question, I hope it is clear what I meant to do. Thanks in advance.
Glad you like the content. Your query is too complex for EF Core. For this, you are best to put it in a SQL view, then query it using the DbContext. Watch this video to find out how to use EF Core with views ruclips.net/video/TMiOAECdodM/видео.html
@@RoundTheCode You misunderstood my question I think. The query is working correctly but I don't understand why the FirstOrDefault().Value in the where clause doesn't throw exception with ef core.
Yes I did misunderstand. Are you using SQL Server to query this? If so, this article may help. learn.microsoft.com/en-us/ef/core/querying/null-comparisons When trying to match a null value in a SQL Server query, it doesn't throw an exception. When LINQ translates the query to SQL, I wonder if it does the same?
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Nice tutorial!
Thanks!
Great video!
I have one question:
Why if I do a query like this in one to many relationship doesn't throw exception in ef core but with linq to object throws:
Suppose I have one object with many serial numbers, because the current serial number is only the last but the table is the historical too,and I want to filter what object has the serial number but only among the most recent of every object, so I did a query like this:
Context.Objects.Include(o=> o.SerialNumbers.Where(s=> s.TypeId==2)).Where(s=> s.SerialNumbers.OrderByDescending(s=>s.Date).FirstOrDefault().Value == passed serial number). FirstOrDefault()
I did an include with condition, but in the where clause I expected that the FirstOrDefault().Value throws exception where the FirstOrDefault () results null, but in ef core this doesn't happen.
There is a explanation to this?
Sorry for my english and my long question, I hope it is clear what I meant to do.
Thanks in advance.
Glad you like the content.
Your query is too complex for EF Core. For this, you are best to put it in a SQL view, then query it using the DbContext.
Watch this video to find out how to use EF Core with views
ruclips.net/video/TMiOAECdodM/видео.html
@@RoundTheCode You misunderstood my question I think.
The query is working correctly but I don't understand why the FirstOrDefault().Value in the where clause doesn't throw exception with ef core.
Yes I did misunderstand.
Are you using SQL Server to query this? If so, this article may help.
learn.microsoft.com/en-us/ef/core/querying/null-comparisons
When trying to match a null value in a SQL Server query, it doesn't throw an exception. When LINQ translates the query to SQL, I wonder if it does the same?