AsSplitQuery will perform separate queries instead of complex joins when returning data from multiple tables.
When using a single query result with data from multiple tables, there is a probability of “cartesian explosion” of duplicate data across many columns and rows.
e.g
var result =dbContext.Student.Where(s=> s.Id == id)
.Include(x => x.Books)
.ThenInclude(x => x.Overdues)
.AsSplitQuery();
Cheers,
Samitha
If you ever wanted to assign an empty string to a value returned from a Linq query, use ?? (null-coalescing operator) to return Empty string in case of null
var qry= from row in context.Table
select new { FieldValue = (field.Value ?? string.Empty) };
Cheers,
Samitha
In C# 8.0, the Switch statements has become more powerful with patterns. All the cases have turned into expressions and become more readable.
Following code illustrates basic usage of new switch.
var action= 1;
var result = operation switch
{
1 => "Action 1",
2 => "Action 2",
3 => "Action 3",
4 => "Action 4",
_ => "No Action performed"
};
Console.WriteLine(result );
More information can be found here.
Chaeers,
Samitha
EF .Net Core retrieves entities from the database with racking enabled, meaning any changes made to the entity are observed and can be automatically saved back to the database.
This automatic monitory feature is not optimal when it comes to read only operations (SELECT statements). To get more information on Tracking Vs Non Tracking queries read following Microsoft article.
As an optimization for read-only queries we can AsNoTracking as shown below. Adding this will stop E EF Core tracking the results, returning in improved performance as EF Core doesn't manage the state of the entity.
var books= dbContext.Books
.AsNoTracking()
.ToList();
Cheers,
Samitha
When working with Enumerable in .Net, there is always a possibility of returning an empty Enumurable if no match is found. Consider the following code.
private IEnumarable<Book> GetBook(string name)
{
if (string.IsNullOrEmpty(name))
return Enumerable.Empty<Book>();
return _dbContext.Book.Where(b => b.Name.ToLower().Contains(name));
}
In the above piece of code Enumerable.Empty method is used to check the null name and return an empty book rather than returning null which can cause runtime exception if the name is not supplied. This is considered as defensive code practice.
Cheers,
Samitha
When building Visual studio you might encounter the error MSB4019: The imported project Microsoft.TextTemplating.targets" was not found.
To fix this error
Entityframework Extensions can be used to improve your performance dramatically.
You can perform: following operations easily.
Read more at https://entityframework-extensions.net/
Cheers,
Samitha