When using a JOIN clause in a SELECT statement, you are typically combining data from ___________ tables.
- Related
- Associated
- Connected
- Linked
The correct option is Option 4: Linked. In SQL, a JOIN clause is used to combine rows from two or more tables based on a related column between them. It links the tables together to create a single, unified dataset for analysis or manipulation.
How can you handle data conflicts when multiple users are trying to modify the same data in a dataset simultaneously?
- Ignore conflicts
- Lock the dataset
- Use optimistic concurrency control
- Use pessimistic concurrency control
Handling data conflicts in ADO.NET involves implementing optimistic concurrency control, where the system assumes that conflicts are rare. When multiple users attempt to modify the same data concurrently, the system checks if the data has been altered since it was retrieved. If the data has changed, it prevents the modification and notifies the user, allowing them to resolve the conflict.
How do you apply sorting to a DataView in ADO.NET?
- By using the Sort property
- By using the Select method with an ORDER BY clause
- By using the Sort method
- By setting the OrderBy property
The correct option is option 3, By using the Sort method. The Sort method allows you to specify the column(s) and the sort order(s) for the DataView. This enables you to arrange the data in the desired sequence, facilitating easier data manipulation and presentation.
Scenario: You need to read data from a large SQL Server database. Which ADO.NET data reader should you use, and why?
- DbDataReader
- OleDbDataReader
- OracleDataReader
- SqlDataReader
SqlDataReader provides the most efficient way to read data from a SQL Server database due to its optimized design specifically for SQL Server. It provides a forward-only, read-only stream of data, reducing memory consumption and increasing performance when dealing with large datasets. OleDbDataReader is used for OLE DB data sources, OracleDataReader is specific to Oracle databases, and DbDataReader is the base class for all ADO.NET data readers, providing more generic functionality.
How can you manage the state of a database connection in ADO.NET?
- By opening and closing the connection manually
- By setting the ConnectionState property
- By using connection pooling
- By using transactions
The state of a database connection in ADO.NET can be managed by setting the ConnectionState property of the SqlConnection object. This property indicates whether the connection is open, closed, connecting, executing a command, or fetching results. By checking and setting this property, developers can ensure that connections are used appropriately and efficiently throughout the application.
Entity Framework allows developers to work with databases using ___________ instead of SQL queries.
- C# (C Sharp)
- JSON (JavaScript Object Notation)
- LINQ (Language Integrated Query)
- XML (eXtensible Markup Language)
Entity Framework allows developers to work with databases using LINQ (Language Integrated Query) instead of SQL queries. LINQ provides a consistent query syntax to work with various data sources, including databases, collections, and XML. It allows developers to write queries using familiar C# syntax, which are then translated into SQL queries by Entity Framework.
When working with optimistic concurrency, ADO.NET uses ___________ columns to track changes made to rows.
- Tracking
- Revision
- Version
- Identification
The correct option is "Version". ADO.NET uses version columns to track changes made to rows when working with optimistic concurrency.
What does LINQ stand for in the context of C# and .NET?
- Language-Integrated Query
- Lightweight Integration Query
- Linear Interpolated Query
- Linking Interactive Query
LINQ stands for Language-Integrated Query. It provides a set of features that allow for querying data directly from C# or VB.NET code, making it easier to interact with various data sources such as databases, XML, and collections.
In a LINQ query, the orderby clause is used to ___________ the elements in the result set.
- Arrange
- Filter
- Sort
- Group
The "orderby" clause in a LINQ query is used to sort the elements in the result set based on specified criteria. Hence, it sorts the elements, not arranges or filters them. "Sort" is the correct option.
Which part of an Entity Data Model (EDM) is responsible for mapping entity properties to database columns?
- Conceptual Layer
- Mapping Layer
- Presentation Layer
- Storage Layer
Mapping Layer