Scenario: You have a DataSet containing sales data, and you need to retrieve all sales records for a specific product category using LINQ to DataSet. Which LINQ clause would you use for filtering the data?
- From
- OrderBy
- Select
- Where
In LINQ to DataSet, the Where clause is used for filtering data based on specified criteria. It allows you to specify conditions to filter the data and retrieve only the records that match those conditions. For this scenario, using the Where clause enables you to filter sales records based on the product category, thus achieving the desired result.
Why are stored procedures commonly used in database applications?
- Stored procedures enhance security by controlling access to database objects and enforcing data integrity.
- Stored procedures facilitate collaboration among developers by providing a centralized code repository.
- Stored procedures improve performance by reducing network traffic and promoting code reuse.
- Stored procedures simplify application development by encapsulating complex business logic.
Stored procedures are commonly used in database applications for several reasons. They improve performance by reducing network traffic, as only the name of the stored procedure and any parameters need to be transmitted instead of the full SQL statements. They promote code reuse by encapsulating frequently used logic, reducing redundancy and making maintenance easier. Stored procedures also enhance security by controlling access to database objects and enforcing data integrity rules. Additionally, they can simplify application development by providing a standardized interface to complex business logic.
The Repeater control allows developers to create ________ HTML or other markup for each item in a dataset.
- Conditional
- Custom
- Dynamic
- Static
The Repeater control in ADO.NET allows developers to dynamically generate HTML or other markup for each item in a dataset. This means that the markup can be generated based on the data retrieved from the dataset, providing flexibility in the presentation of the data.
What is the purpose of the SaveChanges method in Entity Framework when updating data?
- It creates a backup of the current state of entity objects in the context before applying any modifications.
- It discards any changes made to entities in the context without affecting the underlying database.
- It persists all pending changes made to entities in the context to the underlying database.
- It retrieves the latest version of data from the database and updates the entity objects in the context.
The SaveChanges method in Entity Framework is used to persist all pending changes made to entity objects in the context to the underlying database. This includes inserting new records, updating existing ones, and deleting entities as necessary. By calling SaveChanges, the framework ensures that any modifications made within the context are correctly synchronized with the database, maintaining data consistency. This method is essential when updating data as it commits the changes made by the application, making them permanent in the database.
When working with LINQ to Entities, the "Include" method is used to specify ___________ properties to be eagerly loaded.
- Associated
- Joined
- Navigation
- Related
In LINQ to Entities, the "Include" method is used to specify navigation properties to be eagerly loaded. Navigation properties are properties on an entity that allow you to navigate to related entities.
LINQ allows developers to query and manipulate which types of data sources?
- Arrays
- Collections
- Databases
- XML
LINQ (Language Integrated Query) enables developers to query and manipulate collections, databases, XML documents, and any data source that can be queried with LINQ. It's a versatile tool for working with different types of data sources, making it easier to write expressive and powerful queries in C# and other .NET languages.
You are developing an application that needs to retrieve data from an Oracle database and update it using a DataSet. Which type of DataAdapter would you use for this scenario?
- MySqlDataAdapter
- OleDbDataAdapter
- OracleDataAdapter
- SqlDataAdapter
The OracleDataAdapter is specifically designed to work with Oracle databases, making it the appropriate choice for retrieving and updating data from an Oracle database using a DataSet. It provides optimized performance and native support for Oracle databases.
In WinForms, which event is often used to trigger data binding updates?
- ControlChanged
- DataBindingComplete
- DataBindingUpdated
- DataSourceUpdated
In WinForms, the DataSourceUpdated event is often used to trigger data binding updates. This event occurs after the data source has been updated with the new value from the control, allowing for additional processing or validation to be performed.
Which ADO.NET class represents a single table of in-memory data?
- DataTable
- SqlCommand
- SqlConnection
- SqlDataAdapter
The DataTable class in ADO.NET represents a single table of in-memory data. It provides methods and properties to manipulate and interact with the data stored in the table, such as adding rows, deleting rows, or performing queries. It is commonly used for data manipulation and caching within applications.
Scenario: You want to optimize a LINQ to Entities query to minimize the number of database round-trips. What technique or method can you use for this purpose?
- Eager Loading
- Lazy Loading
- Explicit Loading
- AsNoTracking
The correct option is 1. Eager Loading is a technique used in LINQ to Entities to optimize queries by retrieving related data along with the main query results in a single database round-trip. It preloads related entities in advance, reducing subsequent database calls and improving performance.