Navigation in linq.

Question

I'm new in linq c# with navigation . My three table with navigation property but i'm puzlle how to get data multiple table with navigation . Please help me

Sachin Singh · Answer

for child of child return dbcontext.parent .Include(a => a.Children).ThenInclude(c => c.ChildRelationshipType);

Sachin Singh · Answer

go through https://coding.abel.nu/2012/06/dont-use-linqs-join-navigate/

Mageshwaran R · Answer

Hi Sourabh, Please refer this link, https://docs.microsoft.com/en-us/dotnet/framework/data/adonet/ef/language-reference/query-expression-syntax-examples-navigating-relationships#:~:text=Navigation%20properties%20allow%20a%20user,in%20LINQ%20to%20Entities%20queries.

Jignesh Kumar · Answer

Hi Shourabh, When you want bring relational data at same time that time navigation properties used. You can use .Include() to do eager loading in Linq. Lets take Example which will help you, public partial class Student { public Student() { this .Courses = new List (); } public int StudentID { get ; set ; } public string StudentName { get ; set ; } public Nullable int > StandardId { get ; set ; } public byte [] RowVersion { get ; set ; } public virtual Standard Standard { get ; set ; } public virtual StudentAddress StudentAddress { get ; set ; } public virtual List Courses { get ; set ; } } public partial class Standard { public Standard() { this .Teachers = new List (); } public int StandardId { get ; set ; } public string StandardName { get ; set ; } public string Description { get ; set ; } public virtual List Teachers { get ; set ; } } // Now lets do eager loaging using .Include() for Standard using (var context = new DbContext()) { var stud1 = context.Students .Include( "Standard" ) .Where(s => s.StudentName == "Shourabh" ) .FirstOrDefault (); } // No Lets do eager loading for teacher class using (var context = new DbContext()) { var stud1 = context.Students.Include(s => s.Standard.Teachers) .Where(s => s.StudentName == "Bill" ) .FirstOrDefault (); }