Converting SQL to LINQ, Part 1: The Basics (Bill Horst)

MSDN Blog Postings » Converting SQL to LINQ, Part 1: The Basics (Bill Horst)

MSDN Blog Postings » Converting SQL to LINQ, Part 1: The Basics (Bill Horst) — Mon, 19 Nov 2007 23:10:06 GMT

PingBack from http://msdnrss.thecoderblogs.com/2007/11/19/converting-sql-to-linq-part-1-the-basics-bill-horst-2/

re: Converting SQL to LINQ, Part 1: The Basics (Bill Horst)

Csaba — Tue, 20 Nov 2007 15:13:53 GMT

Hi,

Sorry for this comment. I understand that you want me understand this. But, Unfortunatly is excellent example of minimal code that is hard to understand! (Or not understandable at all for me.)

I just cant understand minimal variiations of names like cust Customer Customers when the variations doen't make sense. (Customers is pluralis of Customer for me, then it should be an array or collction of Customers. Not different entities. It goes around in my head.

Should:

"The SQL code examples I'll be using assume a table called Customers and a table called Orders. The VB code examples assume some object named Customers with type IEnumerable(Of Customer) and another object named Orders with type IEnumerable(Of Order). I'll also use two classes, Customer and Order, which are defined below."

Maybe instead be:

The SQL code examples I'll be using assume a table called CustomerSQTable (singularis) and a table called OrderSQLTable (singularis). The VB code examples assume some object named anCustomer (singularis?) with type IEnumerable(Of CustomerClass) and another object named anOrder with type IEnumerable(Of OrderClass). I'll also use two classes, CustomerClass and OrderClass, which are defined below."

And then:

"From cust In Customers _

Select CustomerName = cust.Name, ID = cust.CustomerID _

Order By ID"

Should be rewritten as:

Ehh, well what???

I don't know, someone who has a clear understanding how to name it so it is understandable for me?

Regards

Csaba

re: Converting SQL to LINQ, Part 1: The Basics (Bill Horst)

Rip Dallas — Wed, 21 Nov 2007 17:37:47 GMT

I agree the example is not very good. I get tired of people posting code that demonstrates some technique but that ends up teaching other bad programming techniques.

For example, both classes have been modeled after a relational database and this is teaching poor design. The Order class should not contain a customerId. Foreign keys are a concept of a relational database not object oriented design. Instead the example should have included a property on customers defined as a collection of Order objects.

Please use good examples when trying to teach new concepts.

re: Converting SQL to LINQ, Part 1: The Basics (Bill Horst)

VBTeam — Wed, 21 Nov 2007 19:46:35 GMT

Sorry for any confusion over the code I provided.

First, regarding RDB vs OOP concepts, this series of posts is intended to show how someone with existing SQL code could migrate to LINQ easily. Someone actually performing this sort of task would probably be using a database and our LINQ-to-SQL feature, but I made my code examples to use "In-Memory" objects for simplicity. I tried to model my objects after the Northwind database, since this is something a lot of people would already be familiar with.

Csaba, I want to make sure this is understandable to you. It may start to make more sense after my next post. If not, please let me know and I'll try to adjust the names to be more clear.

Converting SQL to LINQ, Part 3: DISTINCT, WHERE, ORDER BY and Operators (Bill Horst)

The Visual Basic Team — Tue, 04 Dec 2007 22:14:50 GMT

This post assumes you’ve read the previous posts in this series: Converting SQL to LINQ, Part 1: The

Converting SQL to LINQ, Part 2: FROM and SELECT (Bill Horst)

The Visual Basic Team — Tue, 04 Dec 2007 22:17:07 GMT

This post assumes you’ve read Converting SQL to LINQ, Part 1: The Basics . I’ve made the following name

Converting SQL to LINQ, Part 3: DISTINCT, WHERE, ORDER BY and Operators (Bill Horst)

Noticias externas — Tue, 04 Dec 2007 22:23:43 GMT

This post assumes you’ve read the previous posts in this series: Converting SQL to LINQ, Part 1: The

Aprendiendo LINQ para Visual Basic 2008

Jorge Serrano - MVP Visual Developer - Visual Basic — Wed, 05 Dec 2007 09:16:33 GMT

Si quieres aprender LINQ para Visual Basic 2008, quizás te interesen los siguientes artículos que el

Converting SQL to LINQ, Part 4: Functions (Bill Horst)

The Visual Basic Team — Wed, 12 Dec 2007 21:35:52 GMT

This post assumes you’ve read the previous posts in this series: Converting SQL to LINQ, Part 1: The

Converting SQL to LINQ, Part 5: GROUP BY and HAVING (Bill Horst)

The Visual Basic Team — Wed, 19 Dec 2007 03:08:58 GMT

This post assumes you’ve read the previous posts in this series: Converting SQL to LINQ, Part 1: The

Converting SQL to LINQ, Part 5: GROUP BY and HAVING (Bill Horst)

Noticias externas — Wed, 19 Dec 2007 04:00:36 GMT

This post assumes you’ve read the previous posts in this series: Converting SQL to LINQ, Part 1: The

Aprendiendo LINQ para Visual Basic 2008

El blog de Jorge — Thu, 20 Dec 2007 10:16:33 GMT

Si quieres aprender LINQ para Visual Basic 2008, quizás te interesen los siguientes artículos que el

Converting SQL to LINQ, Part 6: Joins (Bill Horst

The Visual Basic Team — Mon, 31 Dec 2007 21:49:06 GMT

This post assumes you’ve read the previous posts in this series: Converting SQL to LINQ, Part 1: The

Converting SQL to LINQ, Part 6: Joins (Bill Horst)

Noticias externas — Mon, 31 Dec 2007 21:57:22 GMT

This post assumes you’ve read the previous posts in this series: Converting SQL to LINQ, Part 1: The

引用:从SQL 到 LINQ, Part 1: 基础(Bill Horst)

zack — Fri, 04 Jan 2008 05:55:20 GMT

引用:从SQL到LINQ,Part1:基础(BillHorst) [原文作者]:BillHorst

[原文链接]:ConvertingSQLtoLINQ,Part1...

Converting SQL to LINQ, Part 7: UNION, TOP, Subqueries (Bill Horst)

The Visual Basic Team — Tue, 08 Jan 2008 22:35:46 GMT

This post assumes you’ve read the previous posts in this series: Converting SQL to LINQ, Part 1: The

Converting SQL to LINQ, Part 7: UNION, TOP, Subqueries (Bill Horst)

Noticias externas — Tue, 08 Jan 2008 23:33:45 GMT

This post assumes you’ve read the previous posts in this series: Converting SQL to LINQ, Part 1: The

Translating your T-SQL brain to LINQ

Hot Topics — Mon, 11 Feb 2008 03:14:50 GMT

Bill Horst of the VIsual Basic team at Microsoft has been writing a great series on Converting SQL to

SQL から LINQ への変換、パート 7 : UNION、TOP、サブクエリ (Bill Horst)

The Visual Basic Team — Thu, 29 May 2008 10:46:24 GMT

ここでは、このシリーズの前の投稿をお読みになっていることを前提としています。 Converting SQL to LINQ, Part 1: The Basics ( 英語 ) Converting SQL