In ADO.NET, what is the role of a DataTable within a dataset?
- Acts as a connection manager
- Holds data retrieved from a data source
- Represents a single table of data in memory
- Stores metadata about the data structure
A DataTable within a dataset serves as an in-memory representation of a single table retrieved from a data source. It holds the actual data rows along with metadata such as column names, data types, and constraints. This allows for disconnected access to data, enabling offline manipulation and processing.
ADO.NET Entity Framework is an Object-Relational Mapping (ORM) tool that helps in bridging the gap between ___________ and ___________.
- Application Layer and Database Layer
- Business Logic and Presentation Layer
- C# and SQL
- Object-Oriented Programming (OOP) and Database Management Systems (DBMS)
ADO.NET Entity Framework bridges the gap between Object-Oriented Programming (OOP) and Database Management Systems (DBMS). It allows developers to work with relational data using domain-specific objects, thus enhancing productivity and reducing development time by abstracting the complexity of database interaction.
In ADO.NET, how can you handle multiple result sets returned by a SELECT statement?
- Using the SqlCommand.ExecuteReader() method
- Using the SqlConnection.Open() method
- Using the SqlDataAdapter.Fill() method
- Using the SqlDataReader.NextResult() method
In ADO.NET, you can handle multiple result sets returned by a SELECT statement using the SqlDataReader.NextResult() method. This method advances the SqlDataReader to the next result set if available. It allows you to iterate through multiple result sets returned by the same command execution.
To add a new row to a DataTable, you can use the ___________ method.
- AddNewRow()
- CreateRow()
- InsertRow()
- NewRow()
The NewRow() method of the DataTable class is used to create a new DataRow with the same schema as the DataTable. This method creates a new DataRow instance but does not add it to the DataRow collection. It simply returns a reference to the new DataRow, which you can then manipulate and add to the DataTable using the Add() method.
Which namespace is commonly used for LINQ in C#?
- System.Collections
- System.Data
- System.Linq
- System.Xml
The System.Linq namespace is commonly used for LINQ in C#. It contains classes and interfaces that support LINQ query operations for various data sources such as collections, arrays, XML, and databases.
In LINQ to Objects, is it possible to query in-memory collections like arrays and lists?
- Depends on the Collection Size
- No
- Sometimes
- Yes
Yes, LINQ to Objects enables querying in-memory collections such as arrays and lists. It provides a powerful and convenient way to manipulate data structures within the application's memory, offering functionalities like filtering, sorting, and projecting data from these collections.
To enable connection pooling, you need to set the "Pooling" attribute in the connection string to ___________.
- FALSE
- No
- TRUE
- Yes
The "Pooling" attribute in the connection string should be set to "True" to enable connection pooling. This allows the .NET framework to manage connection pooling efficiently.
Which ADO.NET class is commonly used to execute SELECT statements and retrieve data from a database?
- SqlCommand
- SqlConnection
- SqlDataAdapter
- SqlDataReader
The SqlDataAdapter class in ADO.NET is commonly used to execute SELECT statements and retrieve data from a database. It acts as a bridge between a dataset and a data source for retrieving and saving data.
In ADO.NET, what does a Data Filter allow you to do with a DataView?
- Aggregate rows
- Filter rows
- Group rows
- Sort rows
A Data Filter in ADO.NET allows you to filter rows in a DataView based on specified criteria. This means you can display only the rows that meet certain conditions, such as those with specific values in certain columns or rows that satisfy a particular expression. Data Filters provide a way to customize the view of data and present only relevant information to the user.
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?
- GetValue, to retrieve the value from the database without considering if it's NULL or not, thus potentially causing errors if not handled properly.
- HasRows, to check if the result set returned by the query contains any rows, which is unrelated to handling NULL values.
- IsDBNull, to check if the value retrieved from the database is NULL, allowing for proper handling of NULL values in the application logic.
- ReadNull, to explicitly read NULL values from the database, enabling better control over how they are handled in the application.
The IsDBNull method of OracleDataReader allows for seamless handling of NULL values by checking if a retrieved value is NULL before processing it further. This helps in avoiding runtime errors and ensures smooth execution of the application logic. Other methods like GetValue do not provide the same level of control over NULL values and may lead to unexpected behavior if not handled properly.
Explain the concept of master-detail data binding in ADO.NET.
- Master-detail data binding in ADO.NET involves creating a hierarchical structure of data controls, where each control is bound to a separate data source.
- Master-detail data binding in ADO.NET involves linking two data-bound controls, where the selection in the master control (e.g., a dropdown or listbox) drives the data displayed in the detail control (e.g., a grid or form).
- Master-detail data binding in ADO.NET is not supported directly and requires custom implementation using event handlers.
- Master-detail data binding in ADO.NET refers to binding data from multiple tables in a database to a single data-bound control, providing a comprehensive view of related data.
Master-detail data binding in ADO.NET is a powerful technique used to represent relationships between data in a database. It allows users to navigate through related data efficiently and provides a seamless user experience. Understanding how to implement and work with master-detail data binding is essential for building complex data-driven applications in ADO.NET.
What is the main advantage of using stored procedures for database operations?
- Enhanced security
- Improved scalability
- Increased performance
- Simplified maintenance
Stored procedures in databases offer increased performance due to their precompiled nature. This means that the execution plan is already generated and stored, reducing overhead each time the procedure is executed.