I have a store procedure as below:
using(DataStoreContext ctx = new DataStoreContext())
{
int value = ctx.RequestProc(filename, message).First().Result;
}
I would like to create Asynchronus access to database to execute this above procedure, where I am using LinqToSql.
I need to create a .XLS file and put it available for download in my .aspx page. this file is needed to have information from database. I'm using Linq to SQL. So I need a C# code for reading from DataBase using Linq and create a .XLS file for download.
View 1 Repliesi have the code for asynchronous call to the database. i execute the sql command into the begin method that will executed onto the separate thread. now i want to execute the another database call asynchronously so that this also execute onto the separate thread. code for one database cal is here....
private SqlConnection con, con1;
private SqlCommand cmd, cmd1;
private SqlDataReader dr, dr1;
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
AddOnPreRenderCompleteAsync(new BeginEventHandler(Begin),
new EndEventHandler(End)
);
}
}
/////////////BEGIN METHOD
IAsyncResult Begin(object sender, EventArgs e,AsyncCallback cb, object state)
{
string connect = "Data Source=.\SQLEXPRESS;Asynchronous Processing=true;AttachDbFilename=|DataDirectory|\Database.mdf;Integrated Security=True;User Instance=True";
con = new SqlConnection(connect);
con.Open();
cmd = new SqlCommand("SELECT FirstName,LastName,Age,Company,Profile FROM Person",con);
return cmd.BeginExecuteReader(cb, state);
}
//////END METHOD
void End(IAsyncResult ar)
{
dr = cmd.EndExecuteReader(ar);
Label2.Text = System.Threading.Thread.CurrentThread.GetHashCode().ToString();
GridView1.DataSource = dr;
GridView1.DataBind();
}
I am trying to create a DataReader to return a counted value from an Access Database. It all works if it finds some rows, but falls apart when there is no total.
My code is as follows (highlights);
[Code]....
The error that gets thrown is:
Description:
An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.IndexOutOfRangeException: BoxesOut
Source Error:
Line 43: if(reader2["BoxesOut"] != System.DBNull.Value)
i am facing some problem in update, edit and even create new data into my access database using data detail view. i am using microsoft visual web developer 2008, i can do the same when sql server database were to tore the data. but when i try to do the same using access database, an application error. may i know whats going wrong? and how to solve this problem?
View 7 RepliesIs there a way to create dynamic access database, tables and it's columns in c# and export or insert the data in it from excel file in c#?
How can I create the Access database and tables at run time using c#?
How can i create dbml file for MS Access or suggest me any other method so that i can use LINQ with MS Access database.
View 4 RepliesI'm new here and really, new to asp.net except the very basic things.
I am trying to create a very simple (I think simple) web form with five textboxes and three dropdown boxes and one submit button. The user enters information in the textbox fields and selects from the dropdown lists (which are populated from the database), hits enter and the database runs the query and returns information on a separate page (or can it return to the same page via panels?) The original page returned to a separate page using server transfer.
I have this page already existing in asp but feel that it would be much better served in asp.net.
Can someone point me to a post where I would guess this has been answered many times?
How do I submit the new data to the database, update the records and return the query?
I have an ASP.net security database which is normally ASPNetDB.MDF however I have created the same database structure in MS Access. All works great. However, I need to add a couple of other tables but I can't find how to do that in VWD. I'm pretty sure I was able to when the first database I created was an MDF file but not in MS Access.
View 5 RepliesI am working on a search engine application and was hoping there was a way to take multiple fields from the database and combine the values (separated by spaces) into a single virtual field, without having to actually add it to the database
Let's say I have 2 fields, FirstName and LastName - can I take these 2 fields and combine them into a Name field where Name = FirstName + " " + LastName
What I'm going to be attempting has a lot more to it than that, but if I can get an example on how to achieve that, I can apply that same principle on a larger scale
ways of doing this with AND/OR, I want to combine multiple fields into a single field
I need to do a database persistence asynchronously. So am using BeginExecuteNonQuery and EndExecuteNonQuery methods.
IAsyncResult Async = cmd.BeginExecuteNonQuery(null, cmd);
--code---
int number= cmdE.EndExecuteNonQuery(result);
Now this will work if i want to update or insert. Now what i want to do is, i need to insert values in a table and i need to retreive the identity column value for the values which are being inserted. So once the values are inserted, how do i retreive the identity column value corresponding to those inserted values. Here am passing null value in BeginExecuteNonQuery method. So what change should i do to retreive the last identity value.
Looking for a good guide to the asynchronous loading of data from the database after 2 seconds from the page_load.I need a method that does not burden the operation site!
View 18 RepliesIs there anything missing in IIS 6.0 that prevents me from (Insert into table) using MS-Access?
Explain: The application works fine under Visual Studio 2008 IDE the insert into table works fine with no error, Also I tested with hosting provider and works fine with no problem. but now I have published the same exact app in a dedicated server windows 2003 with
IIS 6.0 .NET framework 2.0 with latest service pack I gave IIS_WPG write/modify access to the folder where MS-Access database is located and database but at the time of insert an error pop-up. I need to install in the Server or settings in the IIS to recognize my MS-Access db is it some office runtime that I am missing. (BTW I am using OLEDB connection string in my C# )
Using System.Data.OleDb;
I can retrieve data off of it with no problem but when I try to insert is when it fails I thought the problem was Access Rights but I do not think is the case.
I have some datatables in a LinqToSql entity model (edmx) that are structured like this: SalesOpportunity *<-1 User *<-1 Person i.e Many SalesOpportunities / 1 User, Many Users / 1 Person Anyway, My DomainService is SalesOpportunity centric, and I want to serialize info about the person into the metadata class. I can serialize data about the user without any problem like this:
MetaData Class:
<Include("UserName", "UserName")> _
Public User As User
DomainService Class - GetOpportunities()
Return Me.ObjectContext.Opportunities.Include("User")
I've been trying for several hours to get the Person information. If you have any tips, I'd be grateful to hear them.
Here's my problem: I have an IPerson which is implemented by Employee and Student. What I really want is what you see below. One LINQ statement to get each type of IPerson. This works great until I call the method ;). It makes sense as to why I'd get the error, but I am really struggling as to find a decent way to pull all IPerson objects from the DB and avoid putting switch statements all over my application.
[code]....
Above, there is a commented out return statement - that essentially does a .ToList() and forgoes the whole deferred execution thing, creating 2 SQL statements - not ideal.
I'm running Visual Web Developer 2010 Express on Windows XP and I'm having some trouble linking my DataContext to a control.If I create a new "Web Site", add a new LINQ to SQL Class and add the database tables I want, then add a Control such as FormView and choose a new LINQ Data Source Type; my DataContext I created is visible in the list and all work OK.If I do the same after creating a new "Web Application", my DataContext doesn't show up in the list, but if I go into my Code Behind I can access my DataContext through:
Dim db = new ForumDataContext()
Iam facing the problem with creating the Data Access layer using Dataset.xsd file and How to access the data from the file.
View 2 RepliesI'm trying to create a self referencing object using linqTOsql mapping. So far, I am definitely in over my head. Here's the code I have:
[Table]
public class Category
{
[Column(IsPrimaryKey=true, IsDbGenerated=true, AutoSync=AutoSync.OnInsert)]
public Int64 catID { get; set; }
public Int64 parentCatID { get; set; }
[code]...
How to create create variables/properties in master page, and let sub-pages access them? So my master will have a string property HomeUrl How can any page that uses the master page access this property?
View 2 RepliesI am probably doing this wrong but I want to take all words entered in to a text box and return all records that contain any or all of the words. Can any one point me in the right direction?
protected void ldsGvFaqs_Selecting(object sender, LinqDataSourceSelectEventArgs e)
{
if (txbSearch.Text.Length > 0)
{
string temp = string.Empty;
string[] words = txbSearch.Text.Split(' ');
int counter = words.Length;
foreach (var word in words)
{
temp += "Tags.Contains('" + word + "')";
counter -= 1;
if (counter > 0)
{
temp += " || ";
}
}
ldsGvFaqs.Where = temp;
}
}
But I get the following error, Character literal must contain exactly one character.
I have a bunch of tables which are related in various ways, and I drag and drop them into the MSLinqToSQLGenerator, then save etc. But theres a couple tables and a few columns from other tables that don't get recognized in my code, despite repeated regenerations and trying to create a whole new file, it keeps telling me the fields dont exist when I try to use them, meanwhile I'm using other values from the same tables(the ones that where values are missing from) just fine... The Missing tables are defined in the generated classes, as are the values along with property functions... I'm not using any custom tools either... just straight ms visual web developer 2010 express...
View 2 RepliesDim newMem As New Subscription With { _
.First = txtName.Text, _
.Email = txtEmail.Text, _
.dateLastEmail = "1/1/1980", _
.subDate = Now}
dbp.Subscriptions.InsertOnSubmit(newMem)
dbp.SubmitChanges()
The table contains a field called conDate that is nullable, and in this case I want it to remain null. It will get a date value later, when a confirmation is received. If I add .conDate = "1/1/1980", _ I can successfully add the record, but without that line I get System.InvalidOperationException: Nullable object must have a value. I tried this:
Dim DateConfirm As System.Nullable(Of DateTime) = Nothing and adding
.conDate = DateConfirm, _ but that didn't help either. How can I add a record without giving a date to a field I want to remain null?
I'm using MVC 2 with some Models from a LinqToSql project that I built. I see that when I post back to a Controller Action after editing a form that has a DateTime field from the Model, the MVC Html.ValidationMessageFor() helper will nicely display an error beside the Date text box. This seems to happen automatically when the you test ModelState.IsValid() in the Controller Action, as if the MVC model binding automatically knows that the DateTime field cannot be empty.
My question is... I have some other string fields in these LinqToSql generated classes that are Not-Nullable (marked as Not Nullable in Sql Server which passes thourgh to the LinqToSql generated classes), so why doesn't Mr. MVC pick up on those as well and display a "Required" message in the ValidationMessageFor() placeholders I have added for those fields?
Sure, I have successfully added the MetadataType(typeof<t>) buddy classes to cover these Non-nullable string fields, but it sure does seem redundant to add all this metadata in buddy classes when the LinqToSql generated classes already contain enough info that MVC could sniff out. It MVC validation works with DateTime automatically, why not these Not-nullable fields too?
This is my first attempt at updating a database using LINQtoSQL. At least, it's my first if you don't count the tutorials I've followed. Unfortunately, The tutorials that I have found don't offer much more than updating a single table. I'm attempting to update a DB Model that's a bit more complex.
I have a Stream table:
[Code]....
I want a piece of code for asp.net 3.5 using visual basic. and i am using MS access database.
I have two three text boxes and 2 image upload controls and a submit button.
I want a piece of code in which a user can upload images and store it in our database . i want an asp.net visual basic working code. also i need query behind the submit button.