What is the difference between LINQ to SQL and LINQ to Entities?
- LINQ to Entities supports different data sources including relational databases
- LINQ to Entities uses ObjectContext or DbContext for data manipulation.
- LINQ to SQL is designed for relational databases and maps directly to SQL tables.
- LINQ to SQL uses DataContext for data manipulation.
LINQ to SQL is tightly coupled to SQL Server, whereas LINQ to Entities is more flexible and can work with various data sources beyond SQL Server, such as Oracle, MySQL, etc.
How can you execute a stored procedure in ADO.NET?
- By using the SqlCommand object to create a command with the stored procedure name and then calling ExecuteNonQuery.
- By using the SqlConnection object to establish a connection to the database and then calling ExecuteScalar.
- By using the SqlDataAdapter object to fill a DataSet with the results of the stored procedure execution.
- By using the SqlDataReader object to read the results of the stored procedure execution row by row.
You can execute a stored procedure in ADO.NET by creating a SqlCommand object with the stored procedure name and setting its CommandType property to StoredProcedure. Then, you can add parameters to the command if necessary and execute it using the ExecuteNonQuery method to perform operations that don't return data or ExecuteReader method to retrieve data. The ExecuteScalar method is used when the stored procedure returns a single value. The SqlDataAdapter is used for retrieving data into a DataSet, and SqlDataReader is used for reading data row by row.
What is the significance of the CommandType property in an ADO.NET command object?
- It defines the parameters for the SQL command
- It determines the type of SQL command being executed
- It sets the timeout for the command execution
- It specifies the type of database being accessed
The significance of the CommandType property in an ADO.NET command object is that it determines the type of SQL command being executed. It can be set to CommandType.Text for regular SQL queries or CommandType.StoredProcedure for executing stored procedures.
A common approach to resolving data conflicts in ADO.NET is to implement ___________.
- Data encryption
- Data normalization
- Optimistic concurrency control
- Pessimistic concurrency control
Optimistic concurrency control is a strategy used in ADO.NET to handle data conflicts by assuming that conflicts are rare, thereby improving performance.
Performance optimization in hierarchical data involves techniques like ___________ to reduce data retrieval overhead.
- Aggressive loading
- Deferred loading
- Eager loading
- Lazy loading
In hierarchical data, deferred loading techniques are employed to optimize performance by loading related data only when necessary, minimizing the amount of data retrieved from the database at once.
Scenario: You need to implement a custom conflict resolution strategy in your ADO.NET application. What event should you handle to achieve this?
- RowChanged
- RowChanging
- RowUpdated
- RowUpdating
To implement a custom conflict resolution strategy in an ADO.NET application, you should handle the RowUpdating event. This event occurs before changes are sent to the database during an Update operation. By handling this event, you can examine the changes being made and implement your custom logic to resolve conflicts before they are applied to the database.
Which ADO.NET class is responsible for transferring data between a data source and a data-bound control?
- DataAdapter
- SqlCommand
- SqlConnection
- SqlDataReader
The DataAdapter class in ADO.NET is responsible for transferring data between a data source, such as a database, and a data-bound control, such as a DataGridView or ListBox. It acts as a bridge between the data source and the dataset, facilitating the retrieval and manipulation of data.
The CommandType property can be set to ___________ when executing a text-based SQL query.
- StoredProcedure
- TableDirect
- Text
- Function
The correct option is Text. When executing a text-based SQL query using ADO.NET, you can set the CommandType property of the command object to Text. This indicates that the command text contains a SQL query statement to be executed directly against the database. Setting the CommandType to Text is appropriate for executing dynamic SQL queries or stored procedures that return rows.
What is the purpose of the INotifyPropertyChanged interface in data binding?
- It allows the data source to provide information about changes to its properties, enabling automatic updating of bound controls
- It defines methods for controlling data binding behavior and handling data validation
- It provides methods for navigating and manipulating data in a dataset
- It specifies the data source for a control and the specific data member to bind to
The INotifyPropertyChanged interface is essential in data binding because it enables the data source to notify the UI controls when the value of a property changes. This notification mechanism ensures that the bound controls reflect the most up-to-date data from the data source.
The let keyword in LINQ is used to define ___________ that can be reused within the query.
- Constants
- Functions
- Objects
- Variables
In LINQ, the let keyword is used to define variables that can be reused within the query. These variables allow for cleaner and more readable code by providing a way to store intermediate results or calculations for later use within the query.