Q1. What is ADO.NET?
Answer
ADO.NET is a data access technology provided by Microsoft for .NET Framework. It allows developers to connect to databases, execute commands, and retrieve data.
Q2. What are the main components of ADO.NET?
Answer
The main components of ADO.NET are `DataSet`, `DataTable`, `DataAdapter`, `DataReader`, `Command`, `Connection`, and `DataView`.
Q3. What is a DataSet in ADO.NET?
Answer
A `DataSet` is an in-memory representation of data that can hold multiple `DataTable` objects and their relationships.
Q4. What is a DataTable in ADO.NET?
Answer
A `DataTable` represents one table of in-memory data. It is a part of a `DataSet` and can contain rows and columns of data.
Q5. What is a DataAdapter in ADO.NET?
Answer
A `DataAdapter` acts as a bridge between a `DataSet` and a data source. It is used to fill a `DataSet` and update the data source with changes.
Q6. What is a DataReader in ADO.NET?
Answer
A `DataReader` provides a way of reading a forward-only, read-only stream of data from a database.
Q7. What is the difference between DataReader and DataSet?
Answer
`DataReader` is connected and read-only, while `DataSet` is disconnected and can be updated.
Q8. What is a Connection object in ADO.NET?
Answer
A `Connection` object establishes a connection to a data source. Examples include `SqlConnection` for SQL Server.
Q9. What is a Command object in ADO.NET?
Answer
A `Command` object is used to execute SQL commands against a data source.
Q10. What is a DataView in ADO.NET?
Answer
A `DataView` represents a customizable view of a `DataTable` for sorting, filtering, searching, editing, and navigation.
Q11. What is the difference between ExecuteReader, ExecuteScalar, and ExecuteNonQuery?
Answer
`ExecuteReader` returns a `DataReader` object. `ExecuteScalar` returns the first column of the first row. `ExecuteNonQuery` executes a command and returns the number of rows affected.
Q12. What is a connection string in ADO.NET?
Answer
A connection string is a string that contains the information needed to connect to a data source, such as the server name, database name, and credentials.
Q13. How do you handle exceptions in ADO.NET?
Answer
Exceptions in ADO.NET are handled using try-catch blocks to catch and manage database-related errors.
Q14. What is the use of SqlParameter in ADO.NET?
Answer
`SqlParameter` is used to pass parameters to SQL commands, helping to prevent SQL injection attacks.
Q15. What is the difference between connected and disconnected architecture in ADO.NET?
Answer
Connected architecture maintains a continuous connection to the database, while disconnected architecture works with data offline and updates the database when needed.
Q16. What is the purpose of the Fill method in DataAdapter?
Answer
The `Fill` method is used to populate a `DataSet` or `DataTable` with data from a data source.
Q17. What is the purpose of the Update method in DataAdapter?
Answer
The `Update` method is used to save changes made to a `DataSet` back to the data source.
Q18. What is a transaction in ADO.NET?
Answer
A transaction is a sequence of operations performed as a single unit of work. If any operation fails, the entire transaction is rolled back.
Q19. How do you implement transactions in ADO.NET?
Answer
Transactions are implemented using the `BeginTransaction` method of the `Connection` object and managed using `Commit` and `Rollback` methods.
Q20. What is the difference between optimistic and pessimistic concurrency?
Answer
Optimistic concurrency assumes that conflicts are rare and checks for them only when updating data. Pessimistic concurrency locks data to prevent conflicts.
Q21. What is the use of the SqlDataAdapter class?
Answer
`SqlDataAdapter` is used to fill a `DataSet` and update a SQL Server database with changes made to the `DataSet`.
Q22. What is the use of the SqlCommandBuilder class?
Answer
`SqlCommandBuilder` automatically generates SQL commands for `DataAdapter` updates based on a `SelectCommand`.
Q23. What is the difference between DataSet and DataTable?
Answer
A `DataSet` can contain multiple `DataTable` objects and their relationships, while a `DataTable` represents a single table of data.
Q24. How do you bind data to controls in ADO.NET?
Answer
Data binding is done by setting the `DataSource` property of a control to a data object like `DataSet` or `DataTable`.
Q25. What is the use of the SqlConnection class?
Answer
`SqlConnection` is used to establish a connection to a SQL Server database.
Q26. What is the use of the SqlCommand class?
Answer
`SqlCommand` is used to execute SQL commands against a SQL Server database.
Q27. What is the use of the SqlDataReader class?
Answer
`SqlDataReader` provides a way of reading a forward-only, read-only stream of data from a SQL Server database.
Q28. What is the difference between DataSet and DataReader?
Answer
`DataSet` is disconnected and can be updated, while `DataReader` is connected and read-only.
Q29. What is the use of the SqlTransaction class?
Answer
`SqlTransaction` is used to manage transactions in a SQL Server database.
Q30. What is the use of the SqlParameterCollection class?
Answer
`SqlParameterCollection` is a collection of `SqlParameter` objects used to pass parameters to SQL commands.
Q31. What is the purpose of the Clear method in DataTable?
Answer
The `Clear` method is used to remove all rows from a `DataTable`.
Q32. What is the purpose of the AcceptChanges method in DataSet?
Answer
The `AcceptChanges` method commits all changes made to a `DataSet` since it was loaded or the last time `AcceptChanges` was called.
Q33. What is the purpose of the GetChanges method in DataSet?
Answer
The `GetChanges` method returns a copy of the `DataSet` containing only the changes made since it was last loaded or since `AcceptChanges` was called.
Q34. What is the purpose of the RejectChanges method in DataSet?
Answer
The `RejectChanges` method rolls back all changes made to a `DataSet` since it was last loaded or since `AcceptChanges` was called.
Q35. What is the use of the DataRelation class?
Answer
`DataRelation` is used to represent a parent-child relationship between two `DataTable` objects in a `DataSet`.
Q36. What is the use of the DataColumn class?
Answer
`DataColumn` represents the schema of a column in a `DataTable`.
Q37. What is the use of the DataRow class?
Answer
`DataRow` represents a row of data in a `DataTable`.
Q38. What is the difference between DataColumn and DataRow?
Answer
`DataColumn` defines the schema of a column, while `DataRow` represents a row of data.
Q39. What is the purpose of the Select method in DataTable?
Answer
The `Select` method is used to filter rows in a `DataTable` based on a specified criteria.
Q40. What is the purpose of the Compute method in DataTable?
Answer
The `Compute` method is used to perform an aggregate function on the data in a `DataTable`.
Q41. What is the use of the DataViewManager class?
Answer
`DataViewManager` is used to manage a collection of `DataView` objects in a `DataSet`.
Q42. What is the use of the DataViewSetting class?
Answer
`DataViewSetting` is used to define the settings for a `DataView`, such as sort order and row filter.
Q43. What is the purpose of the Find method in DataView?
Answer
The `Find` method is used to locate a row in a `DataView` based on the sort order and primary key values.
Q44. What is the purpose of the AddNew method in DataView?
Answer
The `AddNew` method is used to add a new row to a `DataView`.
Q45. What is the purpose of the Delete method in DataView?
Answer
The `Delete` method is used to delete a row from a `DataView`.
Q46. What is the use of the DataColumnChangeEventHandler delegate?
Answer
`DataColumnChangeEventHandler` is used to handle events that occur when a value in a `DataColumn` changes.
Q47. What is the use of the DataRowChangeEventHandler delegate?
Answer
`DataRowChangeEventHandler` is used to handle events that occur when a `DataRow` changes.
Q48. What is the use of the DataTableNewRowEventHandler delegate?
Answer
`DataTableNewRowEventHandler` is used to handle events that occur when a new row is added to a `DataTable`.
Q49. What is the purpose of the BeginEdit method in DataRow?
Answer
The `BeginEdit` method is used to begin an edit operation on a `DataRow`.
Q50. What is the purpose of the EndEdit method in DataRow?
Answer
The `EndEdit` method is used to end an edit operation on a `DataRow` and accept the changes.
.png)
