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.
When using complex data binding scenarios in WinForms, you may need to work with the ___________ object to control data flow.
- DataBinder
- BindingSource
- DataAdapter
- DataConnector
The correct option is BindingSource. In WinForms, BindingSource is often used in complex data binding scenarios to control the flow of data between data-bound controls and data sources, providing a convenient abstraction layer.
When working with multiple related DataTables, what ADO.NET feature allows you to define relationships between them?
- DataColumnCollection
- DataRelation
- DataSet
- ForeignKeyConstraint
In ADO.NET, DataRelation is used to define relationships between multiple DataTables. It allows you to specify how the rows in one DataTable relate to the rows in another DataTable based on key columns.
When modifying data in datasets, what is the significance of the DataAdapter's Update method?
- Connects to the database
- Ensures changes are saved back to the database
- Executes SQL commands
- Retrieves data from the database
The DataAdapter's Update method is significant because it applies changes made to a DataSet back to the database. It synchronizes changes made in the DataSet with the corresponding rows in the database, ensuring that any modifications, deletions, or additions are reflected in the underlying data source.
In ADO.NET, what are the steps involved in updating data using a DataAdapter?
- Fill the DataSet with data from the database
- Initialize the DataAdapter with appropriate SQL commands
- Modify the data in the DataSet
- Update the database with changes from the DataSet
A DataAdapter in ADO.NET acts as a bridge between a database and a DataSet. To update data, the DataAdapter first fills the DataSet with data from the database, modifies the data within the DataSet, and then updates the database with the changes made in the DataSet.
When working with non-query commands, what does the ExecuteNonQuery method return as a result?
- Error message
- Result set
- Rows affected
- Scalar value
The ExecuteNonQuery method in ADO.NET returns the number of rows affected by the command, typically used with INSERT, UPDATE, DELETE queries. It does not return a result set or a scalar value. If there's an error, it may throw an exception.