ADO.NET Interview Questions and Answers (381)

No, it is readonly and forward only control so we can't edit data in repeater control.

SqlDataReader object. (Note: Even datasets also use SqlDataReader objects internally for retriving data from database.)

No, it just reads the information from its data source

Datagrid is
* one which has advanced features and lets you do lot many things like paging and sorting your data without much effort.
* DataGrid can hold text data, but not linked or embedded objects.


Whereas a DataRepeater is
* which does not have the paging feature but we can do it by coding.
* one which can hold other controls and can embed objects.
* It can embed a Datagrid within it but not viceversa.

Apart from this a Data Repeater
--is used in places where you need more control over the rendering of your data
-- have very flexible templates that give you total control over the formatting of your data

Connection pooling enables an application to use a connection from a pool of connections that do not need to be re-established for each use. Once a connection has been created and placed in a connection pool, an application can reuse that connection without performing the complete connection creation process.

increase the execution time out in web.config (or)increase the connection time out in connection string

A linked server configuration enables SQL Server to execute commands against OLE DB data sources on remote servers. Linked Servers is a concept in SQL Server by which we can add other SQL Server to a Group and query both the SQL Server dbs using T-SQL Statements.
Linked servers offer the following advantages:


1. Remote server access.
2. The ability to issue distributed queries, updates, commands, and transactions on heterogeneous data sources across the enterprise.
3. The ability to address diverse data sources similarly.

With a linked server, you can create very clean, easy to follow, SQL statements that allow remote data to be retrieved, joined and combined with local data. Stored Procedure sp_addlinkedserver, sp_addlinkedsrvlogin will be used add new Linked Server.

Yes,

DataAdapter object can accept either DataTable or DataSet as parameter to fill data from database.

eg.

SqlDataAdapter dAd = new SqlDataAdapter();

DataTable dTable = new DataTable();

DataSet dSet = new DataSet();

----

---

dAd.Fill(dTable); // will also work

dAd.Fill(dSet); // will also work

We should only use DataSet as parameter when we are expecting more than one result set is being returned from database.

In order to create a DataView from a DataTable, use instantiate the DataView object by passing DataTable as parameter in the constructor.

eg.

DataView dView = new DataView(dTable);

1. Connection object is responsible for creating a connection to the database.
2. Record object represents data which is not from the database.
3. Parameter object represents a sql parameter
4. Stream object is responsible to represent data from a text page or web page.

ADO.NET utilizes the power of XML by providing disconnected access to data. This is designed with the help of XML classes in .NET Framework which form the components of single architecture.

DAO is used for database access on windows platform. It creates a work space object in which applications or operations are performed. There are two types of database engines they are Jet database engine and ODBC direct database engine.

• ADO.NET Does Not Depend On Continuously Live Connections
• Database Interactions Are Performed Using Data Commands
• Data Can Be Cached in Datasets
• Datasets Are Independent of Data Sources
• Data Is Persisted as XML
• Schemas Define Data Structures

SQLClient .NET classes are highly optimized for the .net / sqlserver combination and achieve optimal results. The SqlClient data provider is fast. It's faster than the Oracle provider, and faster than accessing database via the OleDb layer. It's faster because it accesses the native library (which automatically gives you better performance), and it was written with lots of help from the SQL Server team.

To add a new row in DataTable, we can use NewRow() method of the DataTable object.(Here assume that there are two columns Name, Address in the DataTable.

DataTable dTable = new DataTable();

DataRow row = null;



for (int i = 0; i < 5; i++)

{

  row = dTable.NewRow ();

  row["Name"] = i + " - Raja";

  row["Address"] = "USA";

  dTable.Rows.Add(row);

}