Wrong comparison of GUID (aka UniqueIdentifier) values

[kind-serge]

SQL Server has a slightly different way of comparing GUID values as opposed to .NET implementation, so operators like Less and Greater return unexpected results with the Effort.
.NET framework compares first 4 bytes (uint), then next 2 bytes (ushort), then next 2 bytes (ushort), then rest of 8 bytes one by one.
And here is an example of how SQL Server does comparison of GUIDs: https://stackoverflow.com/questions/6945878/how-is-a-guid-actually-stored-and-sorted-compared-in-sql-server#answer-49300469

[JonathanMagnan]

Hello @TYROTOXIN ,

Thank for letting us known.

We are currently looking at all open issues to clean/make them, so we will eventually soon check this one as well.

Best Regards,

Jonathan

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Performance Libraries
context.BulkInsert(list, options => options.BatchSize = 1000);
Entity Framework Extensions • Entity Framework Classic • Bulk Operations • Dapper Plus • LinqToSql Plus

Runtime Evaluation
Eval.Execute("x + y", new {x = 1, y = 2}); // return 3
C# Eval Function • SQL Eval Function

[JonathanMagnan]

Hello @TYROTOXIN ,

We started to investigate this issue. However, we are not sure how you use the Less or Greater comparator since that's not supported in C# by default.

Could you provide a code example of how you use it when the provider is SQL Server? Perhaps that will help us to better understand to find a solution.

Best Regards,

Jonathan

[kind-serge]

Yeah, it's very simple. Consider such case:

class Record
{
  public Guid Id { get; set; }
}
class SampleDbContext
{
  DbSet<Record> Records { get; set; }
}

...

// Example 1: Filtering
Guid minId = ...;
var records = dbContext.Records.Where(r => r.Id.CompareTo(minId) >= 0).ToList();

....

// Example 2: Ordering
var records = dbContext.Records.OrderBy(r => r.Id).ToList();

[JonathanMagnan]

Hello @TYROTOXIN ,

Thank for the additional information.