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Question

Hi there,

Which of the following two is better for performance?

1. Requisition req = _context.Requisitions.Where(r => r.Id == id).Include(r=> r.Beneficiary).Include(r=> r.RequisitionStatus).FirstOrDefault();
2. Requisition req = _context.Requisitions.Include(r => r.Beneficiary).Include(r => r.RequisitionStatus).FirstOrDefault(r => r.Id == id);

Thanks in advance

Tarique Iqbal

Answer 1

Hi, @Tarique Iqbal. Welcome to Microsoft Q&A. 

Usually the second method performs better. But the performance difference between the two depends on the specific situation. You could print out the time they take to execute SQL queries for comparison.

protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
{
    optionsBuilder.UseSqlServer("...");
	//Print the executed SQL
    optionsBuilder.LogTo(Console.WriteLine, LogLevel.Information);
}

You could also use Stopwatch to calculate the total time from executing this statement to getting the data.

Stopwatch stopwatch = new Stopwatch();
stopwatch.Start();
Requisition req1 = _context.Requisitions.Where(r => r.Id == id).Include(r => r.Beneficiary).Include(r => r.RequisitionStatus).FirstOrDefault();
stopwatch.Stop();
Console.WriteLine("Method 1: {0} ms", stopwatch.ElapsedMilliseconds);
stopwatch.Reset();
stopwatch.Start();
Requisition req2 = _context.Requisitions.Include(r => r.Beneficiary).Include(r => r.RequisitionStatus).FirstOrDefault(r => r.Id == id);
stopwatch.Stop();
Console.WriteLine("Method 2: {0} ms", stopwatch.ElapsedMilliseconds);

In my test, the second method usually takes 2ms to execute SQL on the same database, and the first method usually takes 60ms.

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