Zlatko Michailov on Entity SQL

Now that SQL Server 2008 is out the door, I’m full throttle on my new job. I’m totally excited about the improvement I’m working on, and I can’t wait to start blogging about it (once it’s out of secrecy.) Today I’m only changing the outlook of my...

I have to admit publically that I’ve decided to take on new challenges unrelated to EDM and Entity Framework. Starting today I’ll be working on the lower levels of the SQL Server Connectivity stack. I’d like to thank all of you who’ve been reading...

The .NET Framework SP1 Beta-compatible version of eSqlBlast is available at http://code.msdn.microsoft.com/esql/Release/ProjectReleases.aspx?ReleaseId=991 . The release includes a source code zip as well. The SP1 Beta distributions of .NET Framework...

Following the spirit of Primer to ConnectionStringBuilder from ADO.NET 2.0, let’s see how the pattern has evolved in Entity Framework. Building an Entity Connection String from Scratch What’s important to keep in mind before we dive into code...

If your app is small enough, i.e. you write your own database schema (for SQL Server) and you write the only app over that schema, you don’t really need Entity Framework. In that case, you may consider LINQ to SQL. Now let’s think big. Let’s say...

MSDN Code Gallery is now live! It’s a place to download compiled binaries rather than source code. The latest eSqlBlast is available at http://code.msdn.com/esql .

I recently blogged about canonical functions in Entity Framework and SQL Server’s LEN() function . The purpose of those two posts was to lay out the foundation for this one, and to allow it to be brief and coherent. Please read those two posts before...

There is a peculiarity around the LEN() function in SQL Server that not many people have realized or paid attention to. It’s the treatment of trailing spaces. The documentation says: “ Returns the number of characters of the specified string expression...

Often, people categorize Entity Framework as an Object/Relational Mapper and try to compare it to other O/R Mappers. I dare say that’s an apples-to-oranges kind of comparison. While Entity Framework does have ORM capabilities, that is only a fraction...

2007.12.18 : Today I posted an update to How to Parse an EntityDataReader - I discovered (and fixed) two bugs in the parsing code. Since the code is taken from eSqlBlast, the same fix should be applied to it too. The code is in project Core, class XmlVisitor...

Entity Framework Beta 3 and related packages are available for public download: · Entity Framework Runtime : http://go.microsoft.com/fwlink/?LinkId=104981 · Entity Framework Tools : http://go.microsoft.com/fwlink/?LinkId=104983 · Entity Framework...

Canonical functions were introduced in the Beta 2 release of Entity Framework. Their purpose is to expose a [virtually] canonical API beyond the core language constructs. Consumers of canonical functions should be aware that Entity Framework defines only...

API = syntax + behavior

Until Beta 2 ObjectQuery’s builder methods used to build a Command Tree. There were multiple problems with that: · Duplicate code - there is already a component that builds Command Trees from Entity SQL. · Caching – Command Trees are expensive to...

The way to get the native SQL generated for an ObjectQuery is exactly the same as for EntityCommand – using the new ToTraceString() method introduced in Beta 3. Previously that would require a similar (even more obscure) pattern that involved ObjectQuery...

With the Beta 3 release, Entity Framework is introducing an easy way to get the native SQL from an EntityCommand. There was public API to get to the native SQL, but the pattern was too obscure, and I don’t want to go into detail. Let’s discuss the new...

This post was intended to be a reply to this question http://forums.microsoft.com/msdn/showpost.aspx?postid=2440161&siteid=1 on the Entity Framework forum, but its size exceeds the forum server limit. Besides, it’s useful in general. So I decided...

Last Friday I blogged about making local variables behave consistently in LINQ to Entities queries . And the solution I recommended was compiled queries. But just today I realized that I haven’t blogged about compiled queries in general yet. The...

LINQ is very nice about referencing local variables without any additional declaration. When I ran my first such LINQ to Entities query, I was ecstatic. The next moment I was puzzled – are the values of those variables picked at compile-time and later...

2007.12.18 : Please accept my apologies – today I discovered (and fixed) two bugs in the parsing code. One is a silly error. The other is that collections should be treated as primitive types and refs with regard to the number of fields. The code bellow...

The attached XSL script neatly renders an Entity Framework CSDL file into HTML. Below is the NorthwindEF model that we’ve been using for our samples, rendered using that XSL script: Northwind Entity Sets Entity Types Complex Types Associations...

A well defined query against a well defined entity data model does not need JOIN . Navigation properties in combination with nesting sub-queries should be used instead. These latter constructs represent task requirements much more closely than JOIN...

On Nov 27, 2007 I'll speak about Query Options for Entity Framework at DevTeach in Vancouver, BC. Following is a preliminary outline of the talk: An overview of the Query Pipeline and the processes that take place there. Shapes of results that...

A query issued through Entity Framework undergoes three main transformations: 1. Compilation 2. Query view expansion 3. Native SQL generation 1. Compilation Compilation is the process of producing a Command Tree. 1.1. Entity SQL 1...

Literals “abc” Value abc ‘abc’ Value abc 1 Value 1 {2} Value 2 {3, 4, 5} ...