I want to use ASP.NET Dynamic Data for my next project, but there is a problem a can't manage to solve. In the database we manage authorization on a per-row basis. For example no user is permitted to see all rows of the Contracts table. So there is a Many to Many Relationship between Contracts and Users. So everytime Dynamic Data performs a Select to show all Contracts it has to look into the ContractUsers junction table to see what contracts the current user is permitted to see (filtered by UserID which will be stored in a session variable). Of course these junction tables should be invisible to the users.
By default Dynamic Data returns all rows of a table, so is it possible to customize this behaviour for every query the user performs?
I want to use Dynamic Data together with LINQ to SQL but if this task would much easier to accomplish using Entity Framework I would look into that too.
Thanks for your help and time.
Implementing such a solution in Dynamic Data it will probably require the creation of a custom Entity Template; not really easy but once done it will not require the creation of custom pages just the editing of the page templates.
I think it will be really usefull to check the excellent work on DD done by S.J.Naughton and presented on his blog.
Greetings, F.
You should not use dynamic data because you need full control over querying and manually write all linq queries to add your data level security. If you still insist on dynamic data be aware that you will still write most of pages yourselves and you will only use dynamic templates. You will have to manually define ever data source and correctly pass where condition to filter results based on logged user.
In addition linq-to-sql is not able to hide junction table and entity framework is able to do that only if junction table contains just two FKs for many-to-many relation. If this table contains any other column you want to use in the application you will have to map it as any other entity and dynamic data will show it as an entity.
Dynamic data are technology for quick creation of simple application where you need to provide access to database through web interface but what you describe is not a simple scenario. You need per record authorization which can differ among entity types.
Related
I'm currently in the process of creating a website/system and was wondering how I can create multiple versions of a table to then be used by many users. The reason for this is primarily due to the amount of information that is needed my each user. Another reason for doing so is a result of each information have been laid out to display the product code and other key information.
This is due to a main table setting a list of data for example prices of a product. To which the user then can set and store data in their own table to be used at a later date and referenced accordingly. Rather than creating multiple columns in the thousands I feel it would be better to simply create different versions of the table.
Instead of creating multiple table, why don't you not create seperate Views in Database based on your User and display that information in table.
Altought, its recommended to use the single same table, and add fields that allow to restrict some data for a particular user, there is some few cases that may be required to have several versions of the table, like the ones you mention.
I have work with a web app. that served several companies, with the same tables, fields, schemas, same web server & databased server, and yet the customers want it separated from other users.
Usually, you create several tables with the same schema, but different id. Your web app. must have a way to select which table or database you are going to use.
Be very careful with this approach, is very difficult to maintain, its better to use some programming techniques to control this scenario, like:
http://en.wikipedia.org/wiki/Multitier_architecture
That allows to have a lot of control over a database app. and allows to change a table or database with thesame schema.
Designing a new application in asp.net 4 I have to make a decision how to use a MS SQL Membership API along with my own data in the MS SQL data base. Firstly I need to store and access user profile data in more flexible manner then the Profile provider supports. Secondly I would like to link other user related information (e.g. Orders).
No matter where you store your aspnetdb tables (in the separate data base or in the same data base with your data), the problem stays how to keep your data synchronized.
After a research I see the following relevant options:
1. Foreign key UserId from asp_Users (suggested in this tutorial).
2. No foreign key - use transactions (suggested here).
3. No foreign key - use customized AccountController (whatever it is, suggested here).
4. Additional table which links Membership UserId (uid) with custom UserId (int).
5. ...
On the one hand I like the first solution as it is quite straightforward and is suggested in an official asp.net tutorial.
On the other hand opponents note quite reasonably that using foreign keys breaks the general idea of providers which are supposed to help separating concerns and to be interchangeable. But unfortunately they do not go much into implementation details so it is not really easy to estimate those suggestions in terms of relevance and ease of implementation.
So what is the best option to approach this? Furthermore how would the implementation look like? Would it be enough to use just additional ADO.NET or LINQ etc code or is it worth implementing a custom Membership and/or Profile Provider?
Thank you in advance.
The first is the simpliest approach. Add the GUID of the user as a foreignkey in the related tables (f.e. Ordered_by). I don't see where it breaks separating concerns. If you want to keep the order-record in database, you also have to keep the user who has ordered, that makes perfectly sense.
I have used option 4 successfully in my current application. I've created a table aspnet_UserID with idUser int as primary-key and fiUser(the GUID of the aspnet_Users) as foreign-key. Here is the model:
(Note: User is the standard aspnet_Users table created via aspnet_regsql.exe and aspnet_UserId is my custom table that maps every Guid with my int-ID)
Now i'm storing only my idUser as FK in all related tables (like in your Order-Table). That has the advantage of less storage and more readable UserID's(i could never remember a GUID). Maybe it's somewhat more separated with this "wrapper-table" but that was not my main intention.
You can change the delete-rule on your foreignkeys if you want to control the behavior. Set it to Cascade if you f.e. want to delete all orders that were ordered by the user you're deleting or set it to no Action if you want to keep this order.
I can't suggest any alternatives for the Profile question because you haven't mentioned what you mean with "need to store and access user profile data in more flexible manner then the Profile provider supports".
You should consider writing your own custom membership provider that uses the tables/data as per your need (instead of using ASP.NET provided schema).
See this MSDn sample (schema, code) for writing a custom provider - this sample uses OLEDB to access database. Yet another sample is here - it uses active directory as a store.
I'm working on an ASP.NET4.0/C# application for a public site that needs to authenticate only the employees that work at the associated business. The idea is for the site to have a CMS such that employees can go in and make changes to certain content without having to work with any html.
My question relates to the design and use of a ASP.NET membership provider. I'm not trying to make the site work with an existing database, so there's no need to create my own MembershipProvider for that purpose. However, since each user is an employee, I want to track additional information such as name and office number. I can think of two readily apparent ways to accomplish this:
Use the default SqlMembershipProvider class. As a result, I would need to add the appropriate tables to my database and create a separate table for any "additional" information I want to store. This effectively creates a vertical partition on the user table, since I would use the asp.net-assigned userID as the primary key of the employee table as well. To retrieve the "additional" information, I could ask the provider for information about the current user and requery the database in the event I want to know anything else.
Create one table for all employee information (including login and password) and create my own custom MembershipProvider and MembershipUser classes with the functionality I desire.
I've also considered the use of profiles to store such information, however, the site will publicly contain employee listings, and these pages will need to access some of this information. As a result, I should probably cache this data and it seems like using the serialized fields that profiles provide would cause a problem.
Thus, purely in regards to design... would it be best to make a distinction between a user and an employee and use the default SqlMembershipProvider and associated tables, or write my own user tables that store the information I need and my own MembershipProvider for accessing that information?
If I understand your question correctly, you'd like to store additional user info within the ASP.NET Membership. I've created a number of sites using the following setup.
Install the default .NET Membership using the aspnet_regsql.exe tool
Create a UserProfile table with a uniqueidentifier (PK) UserID column that is linked via a foreign key to the aspnet_Users table
To access that information, all you need is the UserId of a particular User, then you can query your custom table for more information.
Microsoft has written an excellent post on how to do this.
Good luck!
M
I am doing something similar, using your option 1. Works great for me.
My business logic has some functions for mutating users. It knows when to touch my users table or the Membership functionality.
Using a custom MembershipProvider for this sort of thing will give you more work than you bargained for.
SQL Table profile provider (http://weblogs.asp.net/scottgu/archive/2006/01/10/435038.aspx ) will help you do just that.
You will get the power of the Profiles and on the same time not worry about caching or serialization since this provider stores the profile information in clear database table without any serialization. You can use them directly in your queries.
I need to store a few attributes of an authenticated user (I am using Membership API) and I need to make a choice between using Profiles or adding a new table with UserId as the PK. It appears that using Profiles is quick and needs less work upfront. However, I see the following downsides:
The profile values are squished into a single ntext column. At some point in the future, I will have SQL scripts that may update user's attributes. Querying a ntext column and trying to update a value sounds a little buggy to me.
If I choose to add a new user specific property and would like to assign a default for all the existing users, would it be possible?
My first impression has been that using profiles may cause maintainance headaches in the long run. Thoughts?
There was an article on MSDN (now on ASP.NET http://www.asp.net/downloads/sandbox/table-profile-provider-samples) that discusses how to make a Profile Table Provider. The idea is to store the Profile data in a table versus a row, making it easier to query with just SQL.
More onto that point, SQL Server 2005/2008 provides support for getting data via services and CLR code. You could conceivably access the Profile data via the API instead of the underlying tables directly.
As to point #2, you can set defaults to properties, and while this will not update other profiles immediately, the profile would be updated when next it is accessed.
Seems to me you have answered your own question. If your point 1 is likely to happen, then a SQL table is the only sensible option.
Check out this question...
ASP.NET built in user profile vs. old stile user class/tables
The first hint that the built-in profiles are badly designed is their use of delimited data in a relational database. There are a few cases that delimited data in a RDBMS makes sense, but this is definitely not one of them.
Unless you have a specific reason to use ASP.Net Profiles, I'd suggest you go with the separate tables instead.
In an n-tiered application where you are using custom entities, how do you find yourself handling data needed from lookup tables? Do you create entities for each of these lookup tables or employ some other strategy?
For example. I have a "Ratings" lookup table that will be used to populate a dropdownlist. Would you create a ratings object with a ratingid and rating property and pass that to your UI or is there a more efficient way to go about it?
Appreciate your thoughts.
I'd suggest that the solution will depend on how often the lookup data changes, whether or not it needs to be editable, and whether or not you're enforcing referential integrity at the database. I think it makes the schema more understandable if you put each lookup type into a separate table.
I generally don't create entities for each lookup table, but instead will load most of the common lookups into structures that are easily re-used by the application - for an asp.net app, for example, I'll create hashtables or ordered dictionaries which can easily be bound to most web controls.
And, horror of horrors, I sometimes create a singleton to manage access to all these lookups, which can be stored as static vars or in the cache, depending on requirements.
We seperate out the different look up types into different objects. It seems to be a little more work up front, but it provides us the ability to make changes to each individual object when we need to, such as an addition of additional information to an object.