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).
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 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.
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.
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.
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.
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.
What is an anonymous type in LINQ, and how is it used?
- It is a predefined type in LINQ used for query expressions.
- It is a type created dynamically at runtime to encapsulate data.
- It is a type that can only be used within LINQ queries.
- It is a type with no name used for declaring variables.
An anonymous type in LINQ is a type created dynamically at runtime to encapsulate data. It allows you to define a new type without explicitly declaring a class or struct. Anonymous types are typically used to store the results of query expressions or to project data into a new shape. They are convenient for one-time use cases where defining a formal type would be unnecessary overhead. However, they cannot be used outside of the method or scope where they are defined.
The "Connection Reset" attribute in the connection string is used to ___________ the connection pool.
- Empty
- Flush
- Refresh
- Reset
The "Connection Reset" attribute in the connection string is used to reset the connection pool. When set to "True," it clears the pool of connections when a connection is retrieved from the pool.
When handling concurrency conflicts in Entity Framework, you can use the ___________ property to detect changes made by other users.
- ChangeTracker
- ConcurrencyToken
- Locking
- Timestamp
In Entity Framework, the Timestamp property (also known as RowVersion) is often used to detect changes made by other users. This property is automatically updated by Entity Framework when an entity is modified.
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.
Scenario: In a .NET application, you want to provide users with the ability to sort and filter a large dataset displayed in a DataGridView. Which ADO.NET feature would you utilize for this purpose?
- DataAdapter
- SqlCommandBuilder
- DataView
- DataSet
The correct option is "DataView". A DataView provides a flexible way to sort and filter data from a DataTable or a DataSet. By binding the DataGridView to a DataView that is associated with the dataset or table, users can interactively sort and filter the data displayed in the DataGridView.