DISTINCT on one column in LINQ to Entities

The LINQ expression node type 'Invoke' is not supported in the entity framework's LINQ to Entities.

This problem can be solved using the AsExpandable() method present in LINQKIT by Joe Albahari. He's the same creator of ...PredicateBuilder... that I see you're using....If querying with Entity Framework, change the last line to this:...return objectContext.Products.AsExpandable().Where(predicate);...You can grab LINQKIT DLL ...here... or install i...

Distinct on Multiple Columns Entity Framework LINQ

Using anonymous objects will do the trick:...var data = TESTDB.Where(i => i.ALPHA == 1).Select(i => new {i.A, i.B, i.C}).Distinct();

Linq to Entities Select Distinct

Try using .Distinct() at the end of your query, e.g....(from r in ctx.MyTable where SomeCondition select r).Distinct(); ...http://msdn.microsoft.com/en-us/library/system.linq.enumerable.distinct.aspx...If needed, you can also provide an IEqualityComparer. However, to use the IEqualityComparer, the resulting enumerable must first be materialized us...

Entity Framework Code First Using One column as Primary Key and another as Auto Increment Column

You can also do this with Data Annotations:...public class Sale { [DatabaseGenerated(DatabaseGeneratedOption.Identity)] public int Id { get; set; } [Key] public string TrNo { get; set; } public DateTime Date { get; set; } public int CustomerID { get; set; } public ObservableCollection<SaleDetail> SaleDetails { get; se...

Select distinct on one column only using Entity Framework Code First

After our coop, the final query is:...var query = context.Messages .Where(x => x.IsAFriendshipRequest == false && x.SentTo == userId).Include("SentByUser") .Select(x => new { User = x.SentBy, x.DateUtcSent, x.Body, Name = x.SentByUser.Name }) .Union ( context.Messages .Where(x => x.IsAFriendshipRequest == false &...

Entity framework update one column by increasing the current value by one without select

Here is the solution. You can use the following code:...context.Table.Where(x => x.Field1 > 0).Update(y => new Table { Field2 = y.Field2 + 1 }); ...hope that it helps.

Entity Framework 6 Code First int Identity column value is zero for first row

Your concrete migration class should look "something" like the following:...public class 201707132034165_MyAwesomeDbInitial : DbMigration { #region <Methods> public override void Up() { CreateTable( "dbo.HasOverdrive", c => new { HasOverdriveId = c.Int(nullable: false, identit...

how to select distinct values in a column in entity framework?

Add ToList() call at the end of the expression to materialize the query: ...var contractors = context.ManHoursWorked.Where(j => j.JOCID == jocID).Select(c => c.ContractorName).Distinct().ToList();

One-to-one and one-to-many on the same entity in Entity Framework

It's not necessary to define two different mapping for specific entities. All I need was to map a ...one-to-many... relation via fluent api. ...Here are the changes:...public class Office { // fk field to the entity public Guid ManageId{get;set;} public virtual Person Manager {get; set;} public virtual List<Person> People {get; set...

Entity Framework - One-to-One - ReferentialConstraint is mapped to a store-generated column

By convention EF6 represents the one-to-one relationships using the so called ...Shared Primary Key Association..., where the PK of the dependent entity also serves as FK to the principal entity....In your case, it considers ...Account.Id... to be the FK to ...Customer..., and since it's auto-generated, you get the exception in question....The addi...