ADO.NET Interview Questions

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Answered by: sahu

Member Since Dec-2005 | Answered On : Mar 29th, 2007

Hi All,

Ans:

a) SQLCommand  is used to execute all kind of SQL queries like DML(Insert,  update,Delete) & DDL like(Create table, drop table etc)


b)SQLCommandBuilder object is used to build & execute SQL (DML) queries like select, insert, update & delete.

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Answered by: bb.geetha

Member Since May-2008 | Answered On : Jun 12th, 2008

A Partial class is a class that can be split into two or more classes. This means that a class can be physically separated into other parts of the class within the same namespace. All the parts must use the partial keyword. All the other classes should also have the same access modifier. At the compile time, all the partial classes will be treated as a single class. Let us list some advantages of having partial classes.

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Answered by: knreddy221

Using System.Oledb;OledbConnection con= new OledbConnection ("Provider=SQLOLEDB.1;User Id=sa;Database=Northwind");OledbCommand cmd= new OledbCommand ("select * from table1",con);oledbdatareader dr= new oledbdatareader ();dr= cmd.ExecuteReader();datagrid1.datasource=dr;datagrid1.databind();

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Answered by: Sathiyavathi

 We can do it in ADO.Net 2.0 as

   In your connection string there is an additional attribute named as MARS

and set it as true. MARS stands for Multiple Active Result Sets.

  Ex :

    string connectionString = "Data Source=MSSQL1;" +
    "Initial Catalog=AdventureWorks;Integrated Security=SSPI" +
    "MultipleActiveResultSets=True";

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Answered by: machud

Member Since Apr-2011 | Answered On : Apr 10th, 2011

HTTP Handlers can be used to process custom requests that may not be in the standard supported format like .htm, .aspx, .asmx etc. One example will be RSS feed processing . One can write .rss  handler which can be configured in the IIS to accept and delegate the processing to the custom handler written to produce customized output. There are 3 basic steps that need to be performed to make a HTTP handler work properly .
a. Create Handler calss which implements IHttpHandler interface or IHttpAsyncHandler for Asynchrounous handler. IsReusable property and the ProcessRequest method is must be implememented in the Handler class
b. Register the handler class in the web.config file of the application or machine.config
c. Specify the mapping in IIS (Website->Properties->configuration->mappings) add new extension with executable as "C:WINDOWSMicrosoft.NETFrameworkv2.0.50727aspnet_isapi.dll" ( assumes default installation)

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Answered by: deepti705

Member Since Jan-2010 | Answered On : Jan 2nd, 2010

Fill() method is use to fill the data through DataSource in DataSet

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Answered by: yogeshlcse

Member Since Jul-2009 | Answered On : Feb 17th, 2010

Session.Abandon()

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Answered by: seemu123

Member Since May-2008 | Answered On : Nov 11th, 2008

If you have used OleDB you can use an OleDB connectionstring, if you have
used SQLClient, you have to change it to the OracleClient (standard in
2003).

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Answered by: Pendurti

Member Since Sep-2008 | Answered On : Sep 11th, 2008

There is a method called Execute Non Query. This method executes the Update, Delete etc. 

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Answered by: amitdotchauhan

Member Since Jun-2010 | Answered On : Jun 15th, 2010

Yes.

1. SQLCMD is the utility which supports command line interface to perform SQL operations. Output data in xml file & do opertions!
Refer http://msdn.microsoft.com/en-us/library/ms162773.aspx

2. Alternate way to fetch data is enabling SQL server option which allows to provides data on web in XML format (IDK where it is but yes it was there in SQL 2k). Its data on http so you can read & process it just like a web service but cant perform operations.

I am sure there are other ways too! like

1. Create own database format other then SQL

2. Set up API in other application to fetch/process data in other application & set up custom components to store/process them.

Enjoy!

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Answered by: veluworld

Member Since Jul-2007 | Answered On : Aug 28th, 2008

((DropDownList)GV_chart.Rows[e.RowIndex].FindControl("Dcity1"));

Here GV_Chart is the id of Grid View And DCity is the Name of the dropdown list

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Answered by: Lavanyaaru

Member Since Jan-2008 | Answered On : Jan 29th, 2008

There are 3 versions for each DataRow object.
1.Original
2.Current
3.Proposed

The HasVersion( ) method of the DataRow can determine whether a specific version of the row exists. If the version exists, column values for it can be retrieved using one of the three overloads of the DataRow indexer


The Original version contains the values that were loaded into the row.

The Current version contains the latest version of the data, including the changes made since the data was originally loaded. The Original version isn't available for newly created rows.

A Proposed row version is made available while the row is in edit mode and contains the changes that have been made to the row while it was in edit mode

If CancelEdit( ) , RejectChanges() methods are called, the values in the Proposed version are simply discarded

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Answered by: anjali

DataAdapter

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Answered by: ramakrishnag1982

Member Since Nov-2006 | Answered On : Aug 12th, 2007

1) A DataSet can represent an entire relational database in memory, complete with tables, relations, and views, A Recordset can not.

2) A DataSet is designed to work without any continuing connection to the original data source; Recordset maintains the contentious connection with the original data source.

3) There's no concept of cursor types in a DataSet, They are bulk loaded, while Recordset work with cursors and they are loaded on demand.

4) DataSets have no current record pointer, you can use For Each loops to move through the data. Recordsets have pointers to move through them.