Connection pooling helps in efficiently managing and reusing database ___________.
- connections
- memory
- objects
- resources
Connection pooling in databases refers to the technique of reusing established connections instead of creating new ones, thereby optimizing resource utilization and enhancing performance. It manages the connections to the database, not just the memory or resources. Thus, "connections" is the correct option.
What is data binding in ADO.NET used for?
- Binding data to controls
- Creating stored procedures
- Establishing a connection to the database
- Executing SQL queries
Data binding in ADO.NET refers to the process of connecting data from a data source to controls such as grids, textboxes, or dropdown lists. It enables automatic synchronization of data between the user interface and the underlying data source, simplifying development and enhancing user interaction.
Scenario: You are working with an Oracle database and need to handle NULL values gracefully while reading data. Which method of the OracleDataReader would you use for this purpose?
- GetOracleValue()
- GetString()
- GetValue()
- IsDBNull()
The IsDBNull() method of the OracleDataReader class allows for the graceful handling of NULL values in an Oracle database. It returns true if the specified column contains a NULL value, enabling developers to handle NULLs appropriately in their application logic. GetValue() retrieves the value of the specified column, GetString() returns the value of the specified column as a string, and GetOracleValue() is not a valid method in OracleDataReader.
When working with ADO.NET data binding, the DataBinder class provides methods for ___________ data presentation.
- Formatting
- Validating
- Binding
- Displaying
The DataBinder class in ADO.NET provides methods for binding data to controls, ensuring seamless data presentation. Therefore, the correct option is "Binding".
What is the key difference between DataGrid and DataGridView controls?
- Color scheme
- Licensing cost
- Platform dependency
- Supported features
The key difference between DataGrid and DataGridView controls lies in the supported features. DataGrid is the older control available in Windows Forms, offering basic functionalities for displaying data. DataGridView, introduced in .NET Framework 2.0, provides enhanced features such as data binding, sorting, filtering, and editing capabilities, making it more versatile and powerful compared to DataGrid.
To customize the appearance of cells, you can handle the "___________" event.
- CellClick
- CellFormatting
- DataBindingComplete
- RowValidating
To customize the appearance of cells, you can handle the "CellFormatting" event. This event allows you to modify the visual presentation of individual cells in a DataGridView or DataGrid control based on specified conditions, such as data values or cell locations.
When working with a ListBox control, you can use the ___________ property to set the data field that serves as the value for each item.
- DataTextField
- DataValueField
- DataSource
- DataMember
The correct option is 2. DataValueField. This property is used to set the data field that serves as the value for each item in a ListBox control. It is essential for data binding and displaying meaningful values to users.
In WinForms, what is the difference between one-way and two-way data binding?
- One-way data binding allows data modification only through UI controls
- One-way data binding updates the UI controls when the data source changes
- Two-way data binding requires explicit synchronization between UI and data source
- Two-way data binding updates the data source when the UI controls are modified
One-way data binding updates the UI controls when the data source changes, whereas two-way data binding facilitates bidirectional synchronization, updating the data source when the UI controls are modified and vice versa. This difference is crucial in scenarios where real-time data updates are necessary.
Which ADO.NET feature helps in managing data conflicts during concurrent data access?
- Data Adapter
- Data Reader
- Data Set
- Data Table
ADO.NET Data Set helps in managing data conflicts during concurrent data access. It can store multiple DataTable objects along with relationships, providing a disconnected representation of the data from the data source. This enables offline manipulation of data and conflict resolution before updating the data source.
In ADO.NET, the RowVersion column is used to track ___________.
- Data concurrency
- Data integrity
- Data synchronization
- Data validation
The RowVersion column in ADO.NET is used to track data concurrency, enabling efficient detection of changes and conflicts between different users.
LINQ provides a unified and concise way to query and manipulate ___________ data.
- Object
- Relational
- SQL
- XML
LINQ, or Language Integrated Query, allows developers to query and manipulate objects in various data sources, including objects in memory.
How does a Dataset provide disconnected data access in ADO.NET?
- By storing data retrieved from a database in memory
- By directly querying the database
- By establishing a persistent connection to the database
- By executing stored procedures
A Dataset in ADO.NET provides disconnected data access by storing data retrieved from a database in memory. This allows applications to work with the data without maintaining a constant connection to the database server. The other options are incorrect as they do not describe how disconnected data access is achieved.