OleDbDataAdapter is used to get the data from an Access database.
32. Which object is used to add a relationship between two DataTable objects?
The DataRelation object is used to add relationship between two DataTable objects.
33. What are different types of authentication techniques that are used in connection strings to connect .NET applications with Microsoft SQL Server?
.NET applications can use two different techniques to authenticate and connect with SQL Server. These techniques are as follows:
The Windows Authentication option
The SQL Server Authentication option
34. Explain the new features in ADO.NET Entity Framework 4.0.
ADO.NET Entity Framework 4.0 is introduced in .NET Framework 4.0 and includes the following new features:
Persistence Ignorance – Facilitates you to define your own Plain Old CLR Objects (POCO) which are independent of any specific persistence technology.
Deferred or Lazy Loading – Specifies that related entities can be loaded automatically whenever required. You can enable lazy loading in your application by setting the DeferredLoadingEnabledproperty to true.
Self-Tracking Entities – Refers to the entities that are able to track their own changes. These changes can be passed across process boundaries and saved to the database.
Model-First Development – Allows you to create your own EDM and then generate relational model (database) from that EDM with matching tables and relations.
Built-in Functions – Enables you to use built-in SQL Server functions directly in your queries.
Model-Defined Functions – Enables you to use the functions that are defined in conceptual schema definition language (CSDL).
35. What is the difference between the Clone() and Copy() methods of the DataSet class?
The Clone() method copies only the structure of a DataSet. The copied structure includes all the relation, constraint, and DataTable schemas used by the DataSet. The Clone() method does not copy the data, which is stored in the DataSet.
The Copy() method copies the structure as well as the data stored in the DataSet.
36. What is the use of DataView?
User-defined view of a table is contained in a DataView. A complete table or a small section of table depending on some criteria can be presented by an object of the DataView class. You can use this class to sort and find data within DataTable.
The DataView class has the following methods:
Find() – Finds a row in a DataView by using sort key value.
FindRows() – Uses the sort key value to match it with the columns of DataRowView objects. It returns an array of all the corresponding objects of DataRowView whose columns match with the sort key value.
AddNew() – Adds a new row to the DataView object.
Delete() – Deletes the specified row from the DataView object according to the specified index.