When updating data with Entity Framework, you should call the ___________ method to persist the changes to the database.
- ApplyChanges()
- Commit()
- SaveChanges()
- Update()
To persist changes made to data in Entity Framework, you should call the SaveChanges() method. This method commits the changes to the underlying database, ensuring data consistency.
Setting the Nested property of a DataRelation to ___________ enables multi-level hierarchies.
- 0
- 1
- FALSE
- TRUE
When you set the Nested property of a DataRelation to True, it enables the creation of multi-level hierarchies in your DataSet. This means you can navigate through multiple levels of related data using this DataRelation.
The ParentKeyConstraint ensures that parent keys are ___________ and unique.
- Consistent
- Maintained
- Referenced
- Valid
The ParentKeyConstraint in ADO.NET ensures that the parent keys in a relational database are valid, meaning they exist in the parent table, and unique, ensuring data integrity and referential integrity.
Scenario: In a Windows Forms application, you have a requirement to allow users to select multiple items from a ListBox control. How would you implement this feature?
- Set the SelectionMode property of the ListBox control to MultiExtended or MultiSimple.
- Use a CheckedListBox control instead of a ListBox control.
- Handle the ListBox's ItemCheck event and maintain a collection of selected items manually.
- Enable the MultiSelect property of the ListBox control.
Option 1 is the correct approach. Setting the SelectionMode property of the ListBox control to either MultiExtended or MultiSimple allows users to select multiple items by holding down the Ctrl key or dragging the mouse, respectively. This feature provides a straightforward way to implement multiple item selection in a Windows Forms application using standard ListBox controls.
ADO.NET data providers offer optimized data access for ___________ databases.
- MongoDB
- NoSQL
- Relational
- SQL
ADO.NET provides optimized data access for relational databases such as Microsoft SQL Server, Oracle, MySQL, etc. These databases are structured and follow the relational model.
The Update method of a DataAdapter is used to apply changes from a DataSet back to the ___________.
- DataCommand
- DataReader
- DataTable
- Database
The Update method of a DataAdapter is utilized to apply changes made in the DataSet back to the database. It updates the database with changes made in the local DataSet, ensuring data synchronization between the DataSet and the database.
ADO.NET provides a way to interact with databases using ________.
- Classes and Methods
- Data Access Objects
- Data Providers
- Object-Relational Mapping
ADO.NET relies on Data Providers to interact with databases. Data Providers include classes and methods for connecting to, querying, and manipulating data in various database management systems (DBMS).
To perform CRUD operations with LINQ to SQL, you need to define a ___________.
- DataContext
- SqlConnection
- SqlCommand
- DataAdapter
The correct option is 'DataContext'. In LINQ to SQL, the DataContext class is responsible for connecting to the database and managing the objects retrieved from it. It acts as a bridge between the database and the .NET objects, allowing you to perform Create, Read, Update, and Delete (CRUD) operations on the database using LINQ queries and methods.
In ADO.NET, what is the role of parameters in non-query commands?
- Define command type
- Execute the command
- Handle errors
- Provide values
Parameters in non-query commands of ADO.NET are used to provide values dynamically to the command, helping in executing parameterized queries to interact with the database securely and efficiently.
In Entity Framework, what is the difference between Table Splitting and Entity Splitting when it comes to mapping entities to tables?
- Entity Splitting involves mapping a single entity to multiple tables based on its properties.
- Entity Splitting involves mapping multiple entities to a single table based on their properties.
- Table Splitting involves mapping a single entity to multiple tables based on its properties.
- Table Splitting involves mapping multiple entities to a single table based on their properties.
Table Splitting in Entity Framework allows an entity to be mapped to multiple tables with a one-to-one relationship, where each table represents a subset of the entity's properties. This is useful when dealing with large entities or when certain properties should be stored separately for optimization purposes. Entity Splitting, on the other hand, involves mapping a single entity to multiple tables based on its properties, but with each table containing different sets of properties belonging to the same entity. This allows for more granular control over the database schema and can be beneficial in scenarios where certain properties are rarely accessed or updated separately from the main entity.