The ___________ data provider is used for connecting to Oracle databases in ADO.NET.
- OracleClient
- OLEDB
- SQLClient
- DB2Client
The correct option is OracleClient. OracleClient is the specific ADO.NET data provider used for connecting to Oracle databases. It offers optimized performance and features tailored for Oracle databases. Using a database-specific data provider ensures better compatibility and performance compared to generic providers like SQLClient or OLEDB when working with a particular database management system.
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.
Data binding in WPF supports ___________ and ___________ data binding modes.
- OneTime
- OneToN
- OneWay
- TwoWay
WPF data binding supports both OneWay and TwoWay binding modes. OneWay binding updates the target property when the source property changes, while TwoWay binding allows changes in either the source or target to update the other. These modes provide flexibility in synchronizing data between UI elements and underlying data sources.
When binding data to a DropDownList, you typically set the ___________ property to the data field that will be displayed to the user.
- Display
- Field
- Text
- Value
The correct answer is "Text." When binding data to a DropDownList, you typically set the DataTextField property to the name of the data field that will be displayed to the user. This field represents the text that the user sees in the DropDownList for each item.
In the Code-First approach, what is the role of migrations?
- Migrations are used to create the initial database schema.
- Migrations are used to generate code from an existing database schema.
- Migrations are used to handle data manipulation operations.
- Migrations are used to manage changes to the database schema over time.
In the Code-First approach, migrations play a crucial role in managing changes to the database schema over time. They allow developers to update the database schema in response to changes in the application's data model. By running migrations, developers can apply incremental changes to the database schema without losing existing data. This ensures that the database remains synchronized with the application's evolving data model.