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.
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.
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.
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.
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 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.
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.