You could use the EntityFunctions.DiffDays method EntityFunctions.DiffDays(product.EventDate, DateTime.Now) //this will return the difference in days UPDATE EntityFunctions is now obsolete so you should use DBFunctions instead. System.Data.Entity.DbFunctions.DiffDays(product.EventDate, DateTime.Now)
To show the created SQL commands for debugging in EF using System.Data.Objects; … var sqlQuery = query as ObjectQuery<T>; var sqlTrace = sqlQuery.ToTraceString(); AFAIK there are no commands to create DB’s or do any sort of DDL work. This is design limitation of the “Entity SQL” language The EDMX design surface will map your current … Read more
EF Core 5.0 is introducing Filtered Include soon. var blogs = context.Blogs .Include(e => e.Posts.Where(p => p.Title.Contains(“Cheese”))) .ToList(); Reference: https://learn.microsoft.com/en-us/ef/core/what-is-new/ef-core-5.0/whatsnew#filtered-include
It seams all you want to do is filter your context.Books by some criteria. IEnumerable<Book> books = context.Books.Where(b => someConditions); If you still need the empty IEnumerable you can just call Enumerable.Empty(): IEnumerable<Book> books = Enumerable.Empty<Book>();
EDMX is Visual Studio’s “container” for all things about your Entity Data Model. It contains all the information that is in the CSDL, SSDL, MSL, plus information about the visual layout of the tables in your Visual Studio designer surface. The EDMX file is converted into CSDL, SSDL, MSL (typically embedded as resources in your … Read more
If you are sure the all Ids exist in the database and context does not contain (is not tracking) other entities with the same keys, you can use simple fake (stub) entities: _context.RemoveRange(ids.Select(id => new File { Id = id })); To avoid problem with non existing ids, you can get the existing ids from … Read more
Update/delete from the EDMX is not always functional. If the model doesn’t get updated on clicking Update Model from Database let’s say when you have updated a view/table in the DB, do the following: 1) Delete the view/table from the model diagram 2) Switch the EDMX to xml view (right click the edmx file and … Read more
You want to use the .Include(string) method references in this “Shaping query results” article. var item = from InventoryItem item in db.Inventory.Include(“ItemTypeReference”).Include(“OrderLineItems”) where item.ID == id select item; There is probably a “sql” style syntax for the Includes as well. Also see this article about moving from LINQ-to-SQL to LINQ-to-Entities. For others looking for a … Read more
The only way to get a collection of parents with a filtered children collection in a single database roundtrip is using a projection. It is not possible to use eager loading (Include) because it doesn’t support filtering, Include always loads the whole collection. The explicite loading way shown by @Daz requires one roundtrip per parent … Read more
With EF v4 you can use SqlFunctions.StringConvert. So your code would end looking like this: from s in ctx.Services where SqlFunctions.StringConvert((double)s.Code).StartsWith(“1”) select s EDIT As Rick mentions in his comment, the reason for casting the int to a double (decimal probably works too) is that the function does not have an overload for int.