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Showing posts from 2007

Linq To Sql, Attach, Using a DateTime as Timestamp and large bottle of ibuprofren!!!

Scenario:

You use LINQ to SQL (L2S) as your ORM, you create a business layer that supplies a list of customer entities to the presentation layer. The UI presents the data in a gridview where the user can update the info.

When the user clicks update, it passes a new instance of the entity to your BL method. Now you might be tempted to think that you simply use the Attach method of the Customers table and everythings fine and dandy. Oh that it were true. Be ready for:

"System.InvalidOperationException: An entity can only be attached as modified without original state if it declares a version member or does not have an update check policy."

The entity being passed to your BL here is *not* the same one that went out. It is a new one created by the GridView as part of the update. Thus, it has no idea of the original context and your new context has no idea of it's original state.

If you have add a timestamp column that can be used by L2S to determine if the row…

Fixing Association Lines in the LINQ to SQL Designer

There is a simple fix for when the Linq to Sql designer goes crazy with the number of points on an association line. Simply close the designer, click "Show All Files" in your solution. You should now be able to expand the underlying files used to store info for the designer. Open the dataContextName.dbml.layout file with the XML Editor. Associations are stored in an associationConnector element. Find the correct association and change the following attributes to appear as follows: manuallyRouted="false" fixedFrom="NotFixed" fixedTo="NotFixed" If manuallyRouted doesn't appear, don't worry about it. Save everything and close the file. Reopen the designer and your line still looks weird but as soon as you move one of the objects around, it should fix itself.

Steelers Game!!

Went to STL for the Rams-Steelers game. As we we're driving to the hotel, you'd have thought it was a home game. There were more Steeler nation than Rams fans by far. If you ever want to see a site, Casey Hampton was stretching in front of us. At one point he was doing the exercise where you bring your knee across your body and try to touch it to the ground. You must see it for yourself! Alan Fanaca was also stretching and didn't seem to want to talk. Wish him the best next year. He's given a lot to the team over the years and deserves to get a great contract. Forget the hometown discount!!! The game was excellent! Didn't see Willie get hurt although I remember the play. The opening pass from Ben to Holmes was amazing. Need to work on our coverage. Is it just me, or does it seem that you can throw under DeShea pretty easily?!

Get Asp.Net Profile properties from Sql

Ever wanted to include the profile information from an Asp.Net profile in a query? It’s not that hard once you understand the structure. I’ve written a little function that does all the work. Note: I’m using Sql Server as my repository.

First we need to understand how the profile data is stored. Looking at the aspnet_Profile table, we can see that it stores the information in two columns: PropertyNames and PropertyValuesString.

Looking at PropertyNames we can see that it has a basic structure of Property Name, Data Type, Starting Position and Length. For example, in the string “FirstName:S:0:4:Phone:S:4:10:LastName:S:14:5:” we can see that FirstName is of type string, starts at position 0 and has a length of 4. Notice the zero base for the starting position, we need to correct for that in our function. This means in the PropertyValuesString “John2175551212Smith”, we would start with the first position and proceed 4 characters to get the name.

You might be thinking …

Generate Custom Business Object Properties from SQL Server Tables

In the never ending debate between using datasets and using custom business objects (CBOs), one of the main knocks on CBOs is that they take more time to code. You have to write the properties and create getters and setters for each, code the DB calls, etc.

Of course, you could always get yourself a code generator but those cost money. On the other hand, Sql Server 2005 has made this a little easier with some System Views. Look at the Information_Schema views and you’ll find a whole bunch of really nice info. The one we’re going to use today is the Columns view.

The first steps we need is to be able to convert from Sql datatypes to .Net types. This handy little Sql function will do our conversion for us. You can simply delete the function when our done generating.SET ANSI_NULLS ONGOSET QUOTED_IDENTIFIER ONGO-- =============================================-- Create date: 03/15/2007-- Description: Returns the correct Net datatype-- from Sql datatype-- ============================…