Entity Framework 6 - Knowledge Base (KB)

Select Max in Linq to Entities / Entity SQL with type conversion

I'm trying to create some CRUD functionality for a legacy database and using the Entity Framework as an ORM tool. One table, 'Sites', has a Guid type 'Id' column which is never seen by the users and an integer type 'SiteId' which the users use to identitf...

Retrieve only the first row from a table in Entity Framework

Background:...Entity Framework 4, with SQL Server 2008...Problem:...I have a table ...Order.... Each row has a column ...Timestamp.... ...The user can choose some time in past and I need to get the ...Order... closest to the specified time, but that had o...

GROUP and SUM in Entity Framework

I want to select sum of all (paid) prices of an order item for each customer. Here is SQL command: ...SELECT c.name,SUM(oi.price * oi.count) from customer c JOIN order o ON c.id=o.customer_id JOIN order_item oi ON o.id=oi.order_id JOIN bill b ON b.id=oi.b...

Select only a single column in LINQ

The EntityModel is defined as: ...Personnel has a link to a Country...When executing this code in LinqPad, I see that the SQL which is generated is not optimized (all fields are returned) in the first query ? What am I missing here or doing wrong ?...Quer...

WCF OData Service stored procedure call generates "Operation could destabilize the runtime" error with $select option

I've been trying to call a stored procedure through Entity Framework and WCF Data Services (OData). It returns an entity not a complex type. Following walkthroughs found all over the web (like this ...one...), I came up with this code inside my service:..