How to handle Foreign key for optional field in .NET

Posted by brz dot net on Stack Overflow See other posts from Stack Overflow or by brz dot net
Published on 2010-03-23T09:11:50Z Indexed on 2010/04/10 8:33 UTC
Read the original article Hit count: 230

Filed under:

foreign-key

|

ASP.NET

|

c#

|

sql-server

|

database

What is the best way to handle following situation?

A dropdown(for master table) is optional in a particular form. But, In database table the field is constrained with foreign key. If user don't select from dropdown then It creates problem because of foreign key.

One solution is to create default option in master table and use it in case of blank selection. but in dropdown, we need to handle this to show on top. Is it perfect solution? Is there any other optimized solution for this?

Thanks

© Stack Overflow or respective owner

Related posts about foreign-key

Easy way to observe user activity - how improve my database structure.

as seen on Stack Overflow - Search for 'Stack Overflow'
Welcome, I need some advise to improve perfomence my web application. In the begin I had this structure of database: USER -id (Primary Key) -name -password -email .... PROFILE -user Primary Key, Foreign Key (USER) -birthday -region -photoFile ... … >>> More
Using SET NULL and SET DEFAULT with Foreign Key Constraints

as seen on SQL Team - Search for 'SQL Team'
Cascading Updates and Deletes, introduced with SQL Server 2000, were such an important, crucial feature that it is hard to imagine providing referential integrity without them. One of the new features in SQL Server 2005 that hasn't gotten a lot of press from what I've read is the new options for… >>> More
recursive delete trigger and ON DELETE CASCADE contraints are not deleting everything

as seen on Stack Overflow - Search for 'Stack Overflow'
I have a very simple datamodel that represents a tree structure: The RootEntity is the root of such a tree, it can contain children of type ContainerEntity and of type AtomEntity. The type ContainerEntity again can contain children of type ContainerEntity and of type AtomEntity but can not contain… >>> More
EF4 generates invalid script

as seen on Stack Overflow - Search for 'Stack Overflow'
When I right-click in a .EDMX file and click Generate Database From Model, the resulting script is obviously wrong because of the table names. What it generates is the following script. Note the table names in the DROP TABLE part versus the CREATE TABLE part. Why is this inconsistent? This is obviously… >>> More
ON DELETE RESTRICT Causing Error 150

as seen on Stack Overflow - Search for 'Stack Overflow'
CREATE TABLE project ( id INTEGER NOT NULL AUTO_INCREMENT, created_at DATETIME NOT NULL, name VARCHAR(75) NOT NULL, description LONGTEXT NOT NULL, is_active TINYINT NOT NULL DEFAULT '1', PRIMARY KEY (id), INDEX(name, created_at) ) ENGINE = INNODB; CREATE TABLE role ( … >>> More

Related posts about ASP.NET

Migrating ASP.NET MVC 1.0 applications to ASP.NET MVC 2 RTM

as seen on ASP.net Weblogs - Search for 'ASP.net Weblogs'
Note: ASP.NET MVC 2 RTM isn’t yet released! But this tool will help you get your ASP.NET MVC 1.0 applications ready for when it is! I have updated the MVC App Converter to convert projects from ASP.NET MVC 1.0 to ASP.NET MVC 2 RTM. This should be last the last major change to the MVC App Converter… >>> More
April 14th Links: ASP.NET, ASP.NET MVC, ASP.NET Web API and Visual Studio

as seen on ASP.net Weblogs - Search for 'ASP.net Weblogs'
Here is the latest in my link-listing blog series: ASP.NET Easily overlooked features in VS 11 Express for Web: Good post by Scott Hanselman that highlights a bunch of easily overlooked improvements that are coming to VS 11 (and specifically the free express editions) for web development: unit… >>> More
Use ASP.NET 4 Browser Definitions with ASP.NET 3.5

as seen on ASP.net Weblogs - Search for 'ASP.net Weblogs'
We updated the browser definitions files included with ASP.NET 4 to include information on recent browsers and devices such as Google Chrome and the iPhone. You can use these browser definition files with earlier versions of ASP.NET such as ASP.NET 3 Read More......(read more) >>> More
ASP.NET webforms + ASP.NET Ajax versus ASP.NET MVC and Ajax framework freedom

as seen on Stack Overflow - Search for 'Stack Overflow'
If given the choice, which path would you take? ASP.NET Webforms + ASP.NET AJAX or ASP.NET MVC + JavaScript Framework of your Choice Are there any limitations that ASP.NET Webforms / ASP.NET AJAX has vis-a-vis MVC? >>> More
ASP.NET MVC 2 Released

as seen on ASP.net Weblogs - Search for 'ASP.net Weblogs'
I’m happy to announce that the final release of ASP.NET MVC 2 is now available for VS 2008/Visual Web Developer 2008 Express with ASP.NET 3.5. You can download and install it from the following locations: Download ASP.NET MVC 2 using the Microsoft Web Platform Installer Download… >>> More