In ADO.NET, the Savepoint feature is used for ___________ within a transaction.
- Atomicity
- Consistency
- Durability
- Partial rollback
In ADO.NET, the Savepoint feature is used for partial rollback within a transaction, allowing specific parts of the transaction to be undone while preserving the rest.
How can you improve the performance of Entity Framework queries when dealing with large datasets?
- By avoiding eager loading
- By disabling lazy loading
- By increasing database server memory
- By using pagination
Disabling lazy loading can improve the performance of Entity Framework queries when dealing with large datasets. Lazy loading is the default behavior in Entity Framework, where related entities are loaded from the database only when they are accessed for the first time. This can lead to numerous database round-trips when dealing with large datasets, resulting in poor performance. By disabling lazy loading, all related entities are eagerly loaded along with the main entity, reducing the number of database round-trips and improving query performance. However, it's essential to consider the trade-offs, such as increased memory usage, when disabling lazy loading.
In LINQ to DataSet, the group by clause is used to group data based on ___________ columns.
- Common
- Identical
- Related
- Similar
The group by clause in LINQ to DataSet is used to group data based on related columns. It allows you to organize your data into groups based on a specified column or columns, facilitating easier analysis and processing of grouped data.
The ExecuteReader method returns a ___________ object that can be used to read the result set.
- DataAdapter
- DataReader
- DataSet
- DataView
In .NET, the ExecuteReader method is used to execute a SQL query and retrieve data from a database. It returns a DataReader object, which provides a forward-only, read-only stream of data from the database. The DataReader is efficient for processing large result sets sequentially.
In LINQ to Entities, what is the purpose of the ObjectContext class?
- Facilitates the mapping between the conceptual model and the storage model.
- Manages database connections, transactions, and objects in an entity data model.
- Provides methods for querying and manipulating entity data.
- Represents a set of entities that are tracked for changes.
The ObjectContext class in LINQ to Entities acts as a bridge between the conceptual model (objects) and the storage model (database), managing connections, transactions, and object state tracking.
Data binding in DataGrid and DataGridView controls helps in synchronizing data between the control and the ___________.
- DataAdapter
- DataSet
- DataSource
- DataTable
Data binding in DataGrid and DataGridView controls helps in synchronizing data between the control and the DataSource, which represents the data source for the control.
When should you use the INSERT command in ADO.NET?
- When you want to add new records to the database.
- When you want to execute a stored procedure.
- When you want to modify existing data in the database.
- When you want to retrieve data from the database.
You should use the INSERT command in ADO.NET when you want to add new records to a database table. It allows you to insert data into a specified table in the database.
The ToTable() method on a DataView is used to create a new ___________ from the filtered data.
- DataAdapter
- DataSet
- DataTable
- DataView
The ToTable() method on a DataView is used to convert the filtered data into a new DataTable. This method enables you to extract the filtered data and work with it separately, perhaps for further processing or display purposes.
Entity Framework Code-First approach allows you to define _______ in your code, and the database schema will be generated based on these classes.
- Attributes
- Constraints
- Entities
- Relationships
Entity Framework Code-First approach enables developers to define entities, which are the classes representing the data model, in their code. These entities contain properties that map to the database tables. By defining these entities, developers can specify the structure of the database schema, and Entity Framework will automatically generate the corresponding database based on these classes.
Scenario: Your application allows users to update their profile information in a database. Which ADO.NET command is suitable for updating existing records?
- SqlCommand.ExecuteNonQuery()
- SqlCommand.ExecuteQuery()
- SqlCommand.ExecuteScalar()
- SqlCommand.ExecuteXmlReader()
SqlCommand.ExecuteNonQuery() is used to execute non-query commands, including data manipulation language (DML) queries like UPDATE statements. This command is ideal for tasks that modify the database without returning any data, making it suitable for updating existing records.