DataSource Controls :: Get Data From A LinqDataSource From Code Behind?
Nov 18, 2010
If I have a Linqdatasource that isn't connected to a a bound control on my page how do I use the data source to read data in the code behind. ie
var query = (from x in linqdatasource select x)
What I actually want to do is create a data array (myArray) within the code, read all of the data from the linqdatasource (selecting 1 field to form tableDataArray), then compare the two arrays and then write (insert) those into in myArray that are not already in the datasource to the datasource (ie execute an insert back on the datasource).
How can i retrieve the data in linqdatasource in code behind?i have a dynamic database design with column storing the datatype eg. text, int, date.i need to retrieve the value in order to populate the control and bind it.
I have LinqDataSource ID="LinqDataSource1" with values - EnableDelete="True", EnableInsert="True" EnableUpdate="True" on my ascx page, furthermore GridView, button a few textboxes, where a fill new values, which I would like save in my database. After click on button I insert new value to the table throught in function stored in ascx.vb page. It is works, but I don't know, how I refresh GridView on ascx page. I tried
LinqDataSource1.DataBind() GridView1.DataBind()
without any good result, I must refresh page manualy (F5).
I have a FormView bound to LinqDataSource, that is intended to allow editing of a single product's details, that is selected from a GridView. The LDS has a Where parameter set to point to the GridView control (i.e. a ControlParameter).
Im trying to build a where clause in c# for a LinqDataSource, but I cant get it to work, heres my code
[Code]....
when I set category to 'Concerts' tyhe where clause is
'Category = Concerts'
this generates an error telling me there is no column called 'Concerts'. I assume I somehow have to enclose the search term in quotes, Ive tried single and double quotes, but nothing works.
So I need to take the literal "SELECT....FROM Bay....WHERE Warehouse=1 and ((BAY LIKE '1.0%' or BAY LIKE '2.0%'))I have set up a linqdatasource on my asp page and I want to bind that to a gridview. Here is the start of the HTML:
I'v been using SqlDataSource and ObjectDataSource for a while.I would like to know about LinqDataSource and EntityDataSource. Therefore I have 2 questions to ask.1) Why do we need to use those twos? 2) In which cirmustances (Requirements) developers are using LinqDataSource and EntityDataSource?
i am an asp.net beginner, i am a windows application programmer and currently i am working on big project " Human Resources" and i need to allow the users to apply for jobs using a web page.in windows application, i can use the bindingsource to bind textboxes and comboboxes to the fields of an object from L2S.and to bind the datagrid also to the detailed data and the page will be for inserting issue only,i.e i don't need to bring the data of applicants and certificates from the database, i just need some lookup data like maritalstatusCombo and availableJobsList things to allow the user to choose from.how can i do this using linqdatasource.
I am trying to populate the ListView using LinqDataSource data source but the issue I am having is.I need to load the listview on Search button click action.
IN the page_load I kept like this: =========================================== LinqDS.Selecting += new EventHandler<LinqDataSourceSelectEventArgs>(LinqDS_Selecting);
protected void LinqDS_Selecting(object sender, LinqDataSourceSelectEventArgs e) { e.Result = ObjectDS; } ============================================= This works fine but this happens on page load,i want this binding to happen on button click?is there a way to do this?
I am trying to program the where prameters for this in code behind in C#, and is there really no way to do more than one parameter? Or am I not understanding this correctly? It seems only the 2nd parameter gets executed, no matter which one is at begining. I debug and seems they both get executed fine, but my listview doesn't get filtered and instead only the 2nd paramter works. Look at my code:
Also, if I do myLinq.Where = "division ==1 and someotherInt = 2", it works fine, but if I do two different data types, it will throw error. Since I want to filter with two different data types, hwo do I do this?
I'm having a question about the LinqDataSource. Does anyone know if it's possible to perform multiple inserts with the LinqDataSource? Let's say for example that I have 2 tables.
Table A AID = PK autoincrement Name AddressA FK AddressB FK Table B BID = PK autoincrementStreetNumberPostalCodeCountry
These tables are just examples to clarify my question. Let's say that I have a FormView with a LinqDataSource where the user can enter his name en a billing address (A) en delivery address (B). Now I would like to know if the LinqDataSource is able to insert 2 records in table B and use these ID's to insert them in table A together with the name?
I need to retrieve data using a date as an input parameter. I created a WhereParameter and passed in a date value that I know to exist in the database, but no data is returned. Heres my code
[Code]....
Ive passed in '02/06/2010' as the date, in the database, the Startdate column has several values of '2010-06-02 13:08:50.503' so I guess its not being found because of the time part. Whats the best way to make sure that I retrieve the correct data ? Im not concerned about the time at all, I just need all rows for 02/06/2010.
Where can I find documentation on the syntax that is expected for LinqDataSource.Select? It seems to be different from what I would do with Linq inline in C# code. For example, concatenateing something in Linq I would normally just do this in the projection:
new { FullName = (person.FirstName + " " + person.LastName ) } However, with a LinqDataSource the only way I've found to do this is like this: new ( String.Concat(person.FirstName, " ", person.LastName) as FullName)
I literally spent hours trying to figure this out, and only succeeded when I found a blog where someone gave this verbatim as an example. So I still don't understand why the syntax is different, the braces versus parens, aliasing, Concat operators. Next time I do this I want a better understanding so I am not playing this guessing game. It's like being handed a compiler, and trying to write a program when you don't know what language the compiler compiles.1. Are there different "flavors" of Linq? Like a VB Linq, and C# Linq?2. If so, is the LinqDataSource using a VB flavor of Linq?3. Really, what is really important to me, where can I find documentation on this particular falvor of Linq that the LinqDataSource expects? The documentation for the LinqDataSource itself gives nothing more than extremely simplistic examples.
I have a gridview on a page and based on the row selected I need to fill out a form view (dynamic data enabled) from a linqdatasource. On gridview_sleectedindexchanged I create the linqdatasource and set it as the datasource for the formview. It displays nicely but clicking update returns a "Could not determine a MetaTable" error for the datasource mapped.
THe goal is to create a single page that allows users to select a row then get the appropriate data, create an updateable formview so further edits can be done. Do not want to scaffold.
i am using gridview control and a linqdatasource and its all working fine and i have added the functionlity of searchingBySubject and i added WhereParameters and than binding my gridview (see the code below) but somehow its not returning any rows and i see i have number of rows based on what i am searching.
With the gridview I can create a template field to query across associations but I don't see how its possible to do that with the listview (?). I tried to create associations in the eval fields
(ie productId.Brand) where productId is in the Reviews table and is associated with the Products table - and Brand is a member of the Product table but it was no go?
I am upgrading and re designing my current ASP.NET 2.0 website to ASP.NET 3.5 to take advantage of the 3.5 feature set.As part of the re design I am going to use Linq to SQL classes.
The web based application I am working on is an N-Tier application. In the past I have always used an ObjectDataSource when binding against UI controls.I just read an article about the LinqDataSource.After reading this article I am toying with the idea of using the LinqDataSource for selecting data into controls where I only want to select and not change the data (i.e. drop down list boxes or gridviews that don't perform inserts,updates or deletes).Before I go down this path,I was wondering if this is a bad idea and that I should just stick with the ObjectDataSource?
