Scenario: You are developing an application that needs to execute a complex SQL query with parameters. Which ADO.NET object would you use for this task?
- SqlCommand
- SqlConnection
- SqlDataAdapter
- SqlDataReader
SqlCommand is used to execute SQL commands, including complex queries, with parameters. It allows for parameterized queries, reducing the risk of SQL injection attacks and enhancing performance by reusing execution plans.
When you bind data to a DropDownList control, what property is typically used to display the items to the user?
- DisplayMember
- SelectedValue
- Text
- Value
When binding data to a DropDownList control in ADO.NET, the DisplayMember property is typically used to specify which property of the data source objects should be displayed as the items in the DropDownList. This property allows customization of the displayed text while binding data to the control.
LINQ to SQL provides a convenient way to map database ___________ to .NET objects.
- Tables
- Rows
- Columns
- Views
The correct option is 'Tables'. LINQ to SQL enables developers to map database tables directly to .NET objects, making it easier to work with relational data in an object-oriented manner. Each table in the database corresponds to a class in the LINQ to SQL data context, and each row in the table is represented by an instance of that class. This mapping simplifies data access and manipulation tasks.
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.
In the context of DropDownList controls, what is the purpose of the DataTextField property?
- Defines the field that will be used to identify each item in the DropDownList
- Determines the field that will be used to populate the DropDownList with data
- Sets the text color of the items in the DropDownList
- Specifies the connection string to the database
The DataTextField property of a DropDownList control is used to specify the field from the data source that will be used to populate the control with data. This property helps determine which data field will be displayed as the text for each item in the DropDownList. It's crucial for ensuring that the DropDownList accurately reflects the data retrieved from the database or another data source.
Resource management in ADO.NET includes handling of connections, ___________, and other database-related resources.
- Indexes
- Queries
- Transactions
- Views
In addition to managing connections, ADO.NET also involves handling transactions, which are sets of operations that are treated as a single unit of work. Proper transaction management ensures data integrity and consistency in the database.
In Windows Forms, the ___________ event is commonly used to update the user interface after data changes.
- DataChanged
- DataUpdated
- DataSourceChanged
- DataBindingComplete
The correct option is DataBindingComplete. This event is commonly used in Windows Forms applications to update the user interface after data changes. It occurs after a data-binding operation has finished, allowing developers to perform additional tasks or updates to the user interface based on changes to the data source.
In ADO.NET, what is the purpose of the Connection Pooling feature?
- To automatically update database schemas
- To improve security by encrypting database connections
- To manage the connections between a .NET application and a database
- To optimize network bandwidth usage
Connection Pooling in ADO.NET is used to efficiently manage database connections between a .NET application and a database server. It helps in reusing existing connections, thus reducing the overhead of opening and closing connections frequently. This improves application performance and scalability by minimizing the time spent on establishing new connections.
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, 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.