How does LINQ to Entities handle complex queries involving multiple tables and relationships?
- Relies on stored procedures for complex queries.
- Requires explicit JOIN clauses in LINQ queries.
- Uses automatic query optimization based on the entity model structure.
- Utilizes LINQ queries to generate SQL statements for optimized database access.
LINQ to Entities leverages its query provider to translate LINQ queries into SQL statements, optimizing them for database access and efficiently handling complex joins and relationships within the entity model.
The ExecuteNonQuery method returns the number of ___________ affected by the non-query command.
- Columns
- Databases
- Rows
- Tables
In ADO.NET, the ExecuteNonQuery method is typically used for non-query commands such as INSERT, UPDATE, DELETE, etc. It returns the number of rows affected by the execution of the command.
Deferred execution means that LINQ queries are not executed immediately, but rather, they are executed when the query results are ___________.
- Available
- Fetched
- Enumerated
- Requested
Deferred execution in LINQ means that the query is not executed until the results are requested or enumerated. This allows for more flexibility and optimization in querying large datasets or databases. Thus, the correct option is "Enumerated."
The data reader is connected to the database until you explicitly call the _______ method.
- Close()
- Disconnect()
- Dispose()
- Finish()
The data reader is connected to the database until you explicitly call the Close() method. Calling this method releases the resources associated with the data reader and closes the underlying database connection, preventing unnecessary resource consumption and ensuring proper cleanup.
Scenario: You are developing a Windows Forms application that needs to display and edit data from a database. Which ADO.NET component would you use to store and manage the data in a tabular format?
- SqlConnection
- SqlDataAdapter
- SqlDataReader
- DataTable
DataTable is the correct option. It represents one table of in-memory data. It can be used to store and manage data retrieved from a database or any other data source. SqlConnection is used to establish a connection to a database. SqlDataAdapter is used to populate DataTables with data from the database. SqlDataReader is used to read data from a database in a forward-only, read-only manner.
You need to make changes to the database schema while keeping the existing data intact. Which feature of Entity Framework Code-First should you use?
- Code Migrations
- Data Annotations
- Database Initializer
- Fluent API
Code Migrations is the feature of Entity Framework Code-First that allows you to make changes to the database schema while preserving the existing data. Code Migrations automatically updates the database schema based on changes made to the C# classes, making it easy to evolve the database schema over time without losing data.
LINQ to SQL is specifically designed for working with ___________ data sources.
- File-based
- NoSQL
- Relational
- Web-based
LINQ to SQL is tailored for working with relational databases. It provides an object-relational mapping (ORM) framework to map database objects to .NET objects, enabling seamless interaction with relational data sources.
The SqlCommand.Parameters collection allows you to define and manage ___________ for your parameterized queries.
- data types
- database connections
- query parameters
- stored procedures
The SqlCommand.Parameters collection in ADO.NET allows developers to define and manage query parameters for parameterized SQL queries. This helps prevent SQL injection attacks by separating SQL code from user input data.
Which ADO.NET class is used to execute SQL queries and stored procedures?
- SqlCommand
- SqlConnection
- SqlDataAdapter
- SqlDataReader
The SqlCommand class is used to execute SQL queries and stored procedures in ADO.NET.
How does a DataAdapter facilitate interaction between a database and a DataSet?
- By automatically synchronizing changes between the database and the DataSet
- By creating a direct connection between the DataSet and the database
- By executing SQL queries directly on the DataSet
- By providing methods to fill a DataSet with data from a database and update the database
A DataAdapter in ADO.NET facilitates interaction between a database and a DataSet by providing methods to fill a DataSet with data from a database using the Fill method, and to update the database with changes made in the DataSet using the Update method.