Forms Data Controls :: Access DataSet Throughout Application?
Oct 15, 2010
I want to be able to access my dataset from other protected methods. So far the only way for me to do this is declare my dataset globally (dataset mydatset = new dataset();) and then within my methods I return the dataset after I'm finished filling it with my SqlDataAdaptor. I don't think this is very efficient. Is there a better way of accessing this. I understand when you give the dataset a table you should be able to access it's value. However the dataset becomes null once another method is called??
i have been developing an asp.net application with typed dataset.suddenly after adding a method to one of my tabel adapters and compiling the project this error occurs in compiling dataset: Failed to generate code.object reference not set to an instance of an object.
I am having some difficulties with a particular task. I am creating a support desk intranet application and I am trying to write a method within a class within a namespace which will form a generic database connection which can be called from any of the aspx pages so that I have the dbconnection logic in one place; you know, going along with the 'DRY' (Don't Repeat Yourself) mantra.
The Namespace:
SUPPORTDESK.SQL.dbconnection.pullData()
Objective of the method:
To provide any aspx code behind file with an SQL Server 2005 Express Connection and if possible return the data from an SQL Query. This is where I need advice do I create the method such that it simply forms the connection and returns a DataSet or that it returns an SQLConnection object? If i've got things back to front and upside down don't worry I'm a beginner with ASP.NET. The Method so far:
[Code]....
If I'm on the right track how do I access the data returned in the DataSet?
Codebehind: creating dataset, getting data from sql with adaptor and filling into dataset object, then setting detailsview's datasource. I add 2 button to above template to able to edit data at asp page, and added event handlers:buttons:
[Code]....
My question is, what to do inside the detailsview update event function to able to edit and update data. My method can be wrong too.
I am working on a ASP.NET 2.0 application. I get the following exception sometimes when i access the web application. I believe it is related to the server where the application is hosted? Exception of type 'System.OutOfMemoryException' was thrown. 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.OutOfMemoryException: Exception of type 'System.OutOfMemoryException' was thrown. Source Error: An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below. Stack Trace:
I want to run a SUM on a particular against the DataSet returned by a SqlDataSource. How can I access the DataSet stored in memory that is returned by the SqlDataSource to run this calculation?
I have a FileSystem based asp.net 2.0 app that uses Sql Server 2005 Express database.
I have only one dataset for this app with only 4 tables. After i have completed it to a part, a co-worker have added some Classes to it, which are not in same namespace of myBLL classes.
Then i tried added a new table to the dataset. It like all other tables in that dataset uses SQL Statements to access and manage data.
The problem started after i added that new table. I cannot access it from code. I can access all previous TableAdapters but not this new one.
I would like to write an MVC application that accesses multiple data stores (SQL Server, MySQL, Cloud based, etc.).Most of the examples I see use LINQ to SQL for their data access but I read somewhere that LINQ only supports SQL Server - it may have been an old post.I was wondering what the best way to access these different data stores would be. Can I use the Data Access Application Block from MVC to access these data stores?
I am creating a cascading drop down control for use with some drop down lists. They are filled using datasets which connect to a MS Access database. The first dataset was no problem however now I need to create the second which contains a where clause using a passed parameter (ie the selected value from the first drop down). In examples I have seen on the web the @ symbol is used eg WHERE fubar = @varname
When I try to execute this in the query builder in VS2008 I get two errors:
Error in WHERE clause near '@'. Unable to parse query text.
Followed by:
Executed SQL Statement: SELECT DISTINCT tbl_frame.frame_name, tbl_product.frame, tbl_product.model FROM (tbl_product INNER JOIN tbl_frame ON tbl_product.frame = tbl_frame.frame_id) WHERE(tbl_product.model = @model) Error Source: Microsoft JET Database Engine Error Message: No value given for one or more required parameters. It never promts for a variable. If I change the query to be something like WHERE tbl_product.model = 7 it works.
i have retrieved data from the database and stored in dataset.i have to add an additonal row to it,update the data in data set and delete data from the data set..
I am trying to Export the dataset values into Excel in my application, its working for first time. Again if i click the export button [second time] the button does't cause postback and the entire page is not postback.
We have an ASP.NET 3.5 Web application in which we have faced the below issue:
The application is working fine but suddently at one point application URL prompts for the authentication. When we (the support team) checked the server, we were able to identify that the access was denied for some of the main files (like web.config, default page). When we enabled the access the application started working fine.
I wnat to aacess this path with images in aspx(design-source) side. I successfully tested this with html controls but it contains error with server controls here is the aspx content [Code]....
i have 103 column in database 1 column is id, 1 is user ,1 datetime, 100 button on webpage 1 textbox to input value , button1 clicked then value in textbox will insert into database with user:=user.identity.nam datetime=datetime.now colum4 will get value from textbox......button2 for colum2 and buton100 for column100, if i use dataset i need 100 datataset, some other way to solve it ??
In my project I work with Entity Framework (LINQ to ENTITY). I only have ADO.NET Entity Data Model and a DAL (Data Access Layer). I also get the data due a WCFClientService. I have a gridview that needed to be exported in Excel.
FlexCel is a tool for generating Excel files based on a template. The only thing I see in demo's is that they work with DataSets.
Is there a way to convert the data in my gridview to a virtual DataSet?
I've written the following method to get the data:
I am using visual web developer express 2010 and have two dropdownlists which are feeding parameters to my detailsview. both are set to appenddatabound "true" because I have added a % value texted " select all" to them. Now, before I added the 'select all' options I was able to configure my detailsview dataset query to bring over data using the AND statement which meant that the two buttons when placed on the same page brought over values to my detailsview where both criteria were present but when I try this when the wildcards are used with the select all option in the dropdownlists the same does not apply.
I have the following code: using System; using System.Collections; using System.Configuration; using System.Data; using System.Linq; using System.Web; using System.Web.Security; using System.Web.UI; using System.Web.UI.HtmlControls; using System.Web.UI.WebControls; using System.Web.UI.WebControls.WebParts; using System.Xml.Linq; using Oracle.DataAccess.Client; // ODP.NET Oracle managed provider using Oracle.DataAccess.Types;
namespace MyTestApp { public partial class _Default : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { OracleConnection conn = new OracleConnection("User Id=UID; Password=PWD; Data Source=XE; Pooling=false"); try { conn.Open(); } catch ( OracleException oe ){ Console.WriteLine("ERROR : " + oe.Message); } if ( !Page.IsPostBack ) { if (conn.State == ConnectionState.Open) { // get data GetMoleculesToShow(conn); } } // clean up connection conn.Dispose(); } static void GetMoleculesToShow( OracleConnection conn ){ String division; String rxotc; String molecule_name; String prodnum; String proddesc; String molecule_class; String nonactive; // create command object and set attributes OracleCommand cmd = new OracleCommand("schema.package.procedure", conn); cmd.CommandType = CommandType.StoredProcedure; //Bind values cmd.Parameters.Add("mol_to_show_cur", OracleDbType.RefCursor); cmd.Parameters[0].Direction = ParameterDirection.Output; try { // Execute command, have parameters populated cmd.ExecuteNonQuery(); // Create OracleDataAdapter, data provider object to populate dataset OracleDataAdapter da = new OracleDataAdapter(cmd); //Populate dataset with "molrefcur" DataSet ds = new DataSet(); da.Fill(ds, "mol_to_show_cur", (OracleRefCursor)(cmd.Parameters["mol_to_show_cur"].Value)); //Verify dataset is begin populated //DataTable dt = ds.Tables[0]; //foreach ( DataRow dr in ds.Tables[0].Rows ) //{ // division = dr["division"].ToString(); // rxotc = dr["rxotc"].ToString(); // molecule_name = dr["molecule_name"].ToString(); // prodnum = dr["prodnum"].ToString(); // proddesc = dr["proddesc"].ToString(); // molecule_class = dr["molecule_class"].ToString(); // nonactive = dr["nonactive"].ToString(); //} if (ds.Tables[0].Rows.Count != 0) { // display dataset values GridView gvMolecules = new GridView(); gvMolecules.DataSource = ds.Tables["mol_to_show_cur"].Rows; gvMolecules.DataBind(); } } catch (OracleException oe) { Console.WriteLine("ERROR : " + oe.Message); } finally { cmd.Dispose(); } } } }
The dataset is being populated, however when the page renders, the data nor the gridview are visible. I have tried using both IE and Firefox, binding / not binding the columns, AutoGenerateColumns Y / N with no success. As I am new to all of this ( VS2008, ASP.NET, C# ) I can't help but to think I am overlooking something basic.
I am using the following : - VS 2008 - MS Vista SP2 - Oracle XE ( local )
