Get different results with the same query in T-SQL and LINQ (EF Core) - sql

Question

I'm trying to retrieve records from a database in Azure and for the checks I run T-SQL queries directly and then pass them to LINQ against the EF Core context, but I'm running into this problem.
select FechaOrientativa,id, Archivo, Estado, Estudiar, Descripcion
from Concursos
where FechaOrientativa>=CAST( GETDATE() AS Date ) and Estudiar='pt'
order by FechaOrientativa, Archivo, Estado
When I filter for the records with FechaOrientativa greater than or equal to Today, the Estudiar field is equal to 'pt', I get 2,296 records.
Now in Angular, I do http.Get to my Web API where I execute the following:
[HttpGet("sintratar")]
public async Task<ActionResult<IEnumerable<Concurso>>> GetConcursosSinTratar()
{
return await _context.Concursos.Where(c => c.Estudiar == "pt" && c.FechaOrientativa >= DateTime.Now).OrderBy(c => c.FechaOrientativa).ToListAsync();
}
And to my surprise, I receive only 2,151 records and I can't find an explanation.
Any idea, please?
Thanks.

Answer 1

Compare both SQL and EF LINQ queries, the difference is:
From
Query/Code
Result
SQL
CAST( GETDATE() AS Date )
Returns current Date without Time.
EF LINQ
DateTime.Now
Returns current Date with Time.
Hence the queried results are different.
(Example: Only queried records with the date-time field equal/after the query date-time).
From Date and time functions, you are looking for DateTime.Today.
DateTime.Today
CONVERT(date, GETDATE())
return await _context.Concursos
.Where(c => c.Estudiar == "pt" && c.FechaOrientativa >= DateTime.Today)
.OrderBy(c => c.FechaOrientativa)
.ToListAsync();
Or you can use the SQL query in EF Core with .FromSqlRaw().
return await _context.Concursos
.FromSqlRaw(#"select FechaOrientativa,id, Archivo, Estado, Estudiar, Descripcion
from Concursos
where FechaOrientativa>=CAST( GETDATE() AS Date ) and Estudiar='pt'
order by FechaOrientativa, Archivo, Estado")
.ToList();