Forgive what is probably a question that get's asked a lot, but I'm just not getting it. I've searched quite a bit, but I can't quite see clearly from other's posts what I'm missing
It basically comes down to using vb asp.net 2005 and linked tables that have a manny-to-manny relationships, while using a checkbox list.
Can someone please describe, or point to a walkthrough that helps me through this concept? I'd really like to see an example. I'd also like to see how it's done in classic asp or VB asp.net 2.0 so that I can see more fundamentally how it works, before venturing into the new entity framework, and LINQ.
If there are two tables (say People and Catagories) and they are related with a linked table (PeopleCategories), how might I use a FormView in ASP.net to first display, but ultimately edit, insert or delete one or all the categories that are linked to that People record with the linking table. If I can really fully understand this, I would be very, very, very thankful.
Related
I've tried to do my homework on this...
I'm migrating a site from classic asp to asp.net 4.0
Before I rework all the code, I wanted to get clarification that the way i think my database code should be updated is fairly correct. (I'm using SQLClient objects)
First, when old code would use forward only recordsets or access single record/value, I'm fairly sure i'd use SqlCommand and SqlDataReader. That is pretty straightforward.
Now, when my old code navigates a recordset (movePrevious, find, etc.)... I believe the way to go is with SqlDataAdapter and DataTable to retrieve the data and DataView to filter/find/navigate the data.
I'n looking to do a quick migration... i don't want to get too bogged down in the new entity framework... so - just trying to stick with similar objects/logic.
I know this is one of those questions that doesn't really have a right/wrong answer... and I think that is part of my problem in finding an answer - there are so many.
Thanks,
bill g
I answered something similar here.
You only really need to know about the database bit here. For you it's a really good point to start as you mean to go on.
It terms of how deal with the data returned, it's up to you. I'd recommend custom class style dataset approach which will make life easier in the long run but of course in the short term, you'll have to generate them all which can be made easier by CodeSmith*. That in itself has an upfront cost but will, again, save time in the long run.
*Other code generation tools are available.
If your main issue is the database I propose to move and learn the Subsonic 2 (not subsonic 3, too slow) or any other DAL.
See here some examples:
http://subsonicproject.com/docs/Main_Page
Take some time to understand it, make some tests, see what really do, after wille you can't do with out it, but you need some time to understand the logic, and setup it to your project.
Get this project to play with and see some dal in action, ready to run.
I just started working on an asp.net / C#.net application that is going to call a number of different procedures. The -only- thing these procedures do is create database table views, and the only thing I want to do is to store the information in variables. Then pick out which columns I want to convert to JSON, and then make a JSON string. I've actually written code for that in C#.net already, which is smaller, but since I switched to asp.net mvc I'm a little unsure if I should keep it or go with the whole Linq thing.
I checked out the Linq --> SQL drag & drop functionality, and that instantly created about 200 lines of code with set & get methods and everything.
So my question is, is it still worth using Linq even for just extracting data? Eventually this data will be fed to a javascript timeline, which is where I was told MVC would be highly useful with regards to Ajax functionality.
Since you are only using LINQ-to-SQL for data retrieval, I can't think of a single reason NOT to fully utilize it. I've been working on an MVC 1.0 project since last April. During that time, I've had to quickly become familiar with a number of technologies, LINQ-to-SQL being one of them. Get comfortable with it, and also look at the repository pattern...you will be very content and things will go relatively smoothly.
Now, when you get to INSERTs and UPDATEs, things are going to get a little more sticky. LINQ-to-SQL is still up to the job, but you'll need to understand how things work internally a little better. I highly recommend "Pro LINQ (Language Integrated Query) in C# 2008" by Joseph C. Rattz, Jr. The sections covering LINQ-to-SQL easily take up over a third of the book with detailed examples.
As far as the JSON objects go, LINQ-to-SQL's biggest contribution is that it allowed me not to have to worry about creating specialized views or stored procedures just to handle those one-off-types of data retrievals. My current project has a database of 65 tables...NO stored procedures. I can do filters, unions, multi-level joins...and it's all maintained in the application. Sweet...
Yes, it's totally worth it!
LINQ2SQL provides you a great subsurface to retrieve and save data to.
However, you'll need to implement your own Repository Pattern as you dig deeper into ASP.NET MVC.
And during the implementation of the Repository and the required (and even custom / webapp-state based) Queries, you'll be very glad to have all the power available at your fingertips that LINQ provides.
LINQ only adds to the available toolkit you can lean on when creating code. Even if you are using LINQ in a trivial way now, implement it, get familiar with it, and take advantage of the power it gives you both on this project and future projects.
Linq2Sql is quiet good for creating select queries. As it is appearing that you need to create JSON objects from database views it will be quiet useful
I am trying out DevExpress Xtrareports, but have asimple problem that I am not able to find an answer to.
In an Asp.net website project, I want to add a business object to my report as a datasource and then drag and drop the fields from my new business object data source onto the report designer.
Can some one help explain how i do this.
I asssume I have just missed something.
Thanks
Ian
One way to solve this would be to give the designer a DataSet with one or more DataTables representing your business object. You would of course have to write some code to convert your business object to the data table and back.
As a side note DevExpress have a really good support forum and I have always gotten answers to my questions regarding their products. I recommend you try your question there unless you get a really good answer.
I've been looking into ASP.NET Dynamic Data and how it does scaffolding and routing. I've only scratched the surface, but it's looking like I'd have to create a template for each table that I didn't want to display all columns the same way.
My first impression after looking at dynamic data is that it would seem like less time on the programmer to have to edit one-time generated user controls rather than build a template for each table that doesn't have a uniform display behavior.
What proven solutions are people currently using that help ease the laborious tasks of creating ASP.NET CRUD type user controls?
Thanks
In ASP.NET webforms we use CodeSmith. From a single entity we generate admin pages, codebehinds, service layers, data layers and db stored procedures. All in a matter of seconds. I'd recommend you check it our for quickly building the crud in your apps.
We're actually working on our own code generation tool. It has already proven to work perfectly on the lower layers and now we're on the way to extend it for the presentation layer, that is for generating user controls.
I've not looked into dynamic data (although I'd like to when I have some time) but my biggest fear is always to lose flexibility. The problem is that these front-ends are then maybe generated dynamically each time based on some template and editing, especially bringing in special customer wishes becomes quite difficult. For small standard apps it may work perfectly though.
What we're therefore doing is to "generate" these usercontrols based on a set of standard custom server controls we've developed, but we'll generate just the first time from some static information about the entities in our application. Then you can continue customizing.
Such systems should help the developer, improving his development speed, doing the initial awkward work but then they should give him the flexibility to modify till the maximum. They should not add additional complexity...
I used .netTiers CodeSmith templates long time ago (years) and it was proven so strong, so, it must be more than great now.
I know a (big) company who have built a customization engine (allowing GUI for internal company options) around those templates to use them in most of their applications and were so successful.
I've used http://www.ironspeed.com/ in the past which has been great. Saved us MONTHS of time on our last project which has a big DB, so the cost is worth it. But it looks a bit ugly and can be tricky to update the DB schema once you've generated.
Obviously not much widespread use out there other than whats provided in Visual Studio.
Have a look at Blinq.
I've received a project for internal use. My application has to store about 100 rows of meta data of a game and each row has about 15 fields maximum. Fields can be game name, game category, maker, source code path, etc. I will most likely have to join about 5-10 tables for each row of record. Only a few people are using it and will receive very little hits. Speed performance is not a much of an issue. The rows of data I have to present must be sortable and searchable
My current solution is to use ASP.NET's GridView control with ASP.NET's AJAX UpdatePanel to give it that ajax feel. I'm thinking of using LINQ-to-SQL as my data access layer. I'm thinking of building my own custom search engine but if there's an existing control that has this feature already, i would prefer to use that; anyone know of such control exist? Anyways what do you guys think?
Update #1:
I'm looking into creating a DynamicData website. Any have thoughts on that?
Use ext.js!
Look at the Grid Samples, its a very shallow learning curve and provides you with amazing results in little to no time.
http://extjs.com/products/extjs/
Basically, you expose your data via a web service (asmx or WCF, your choice), throw the Ext.Js grid onto your html/aspx page and point it at your webservice. Configure the control for things like sorting/searching/expanding/grouping/paging etc (use the api reference http://extjs.com/deploy/dev/docs/).
ASP.NET Dynamic Data looks really cool, particularly for sites where you've got:
lots of data
not a lot of worries about performance
no / little desire to skin / design the site
no / little desire to extend existing / write new functionality.
So I'd say that's a good match for your project.
Gridview is your best bet. It's so powerful if you know how to use it correctly. It does automatic sorting and if you can code pretty well you can get the data to be filterable(if that's a word). It also makes the Connection to the database for you....so in my opinion, you can't beat the gridview when it comes to reports like that.