In ADO.NET, what is a Dataset used for?
- Represents a connection to the database
- Represents a group of DataTables
- Represents a single table of in-memory data
- Stores a collection of records from a database
A DataSet in ADO.NET serves as an in-memory representation of a complete set of data, typically including multiple DataTables, relationships between them, and constraints. It allows for offline manipulation and caching of data, often used in disconnected scenarios or when working with multiple related tables.
In Entity Framework, what happens if you don't specify a mapping for an entity class?
- Entity Framework creates a default mapping based on naming conventions
- Entity Framework creates a new table with default columns
- Entity Framework ignores the entity class
- Entity Framework throws an error during model creation
In Entity Framework, if you don't specify a mapping for an entity class, Entity Framework creates a default mapping based on naming conventions. This means that the table name will be inferred from the entity class name, and column names will be inferred from the property names.
What is the purpose of using the .AsNoTracking() method in LINQ to Entities when optimizing queries?
- Executes a query synchronously
- Forces immediate execution of a query
- Prevents entities from being tracked by the DbContext
- Tracks changes to entities for update operations
The .AsNoTracking() method in LINQ to Entities is used to prevent entities from being tracked by the DbContext. This can improve performance in scenarios where entities are read but not modified, as tracking entities that won't be updated is unnecessary overhead. However, it's essential to consider the trade-offs, as using .AsNoTracking() means entities will not be automatically updated with changes made in the database.
What is the significance of the DataAdapter's FillSchema method when populating a dataset?
- It creates a new dataset based on the schema of the data source.
- It defines the schema of the dataset based on the schema of the data source.
- It fills the dataset with data from the data source.
- It updates the schema of the data source.
The significance of the DataAdapter's FillSchema method is that it defines the schema of the dataset based on the schema of the data source. This allows for the creation of a dataset with the appropriate structure to accommodate the data retrieved from the data source. It is particularly useful when the dataset needs to be populated with data from a data source whose schema may change over time.
LINQ queries can be written in both query syntax and ___________ syntax.
- Join
- Method
- Select
- Update
LINQ queries can be written in both query syntax and method syntax. Method syntax involves using extension methods and lambda expressions, making "Method" the correct option for the second blank.
When using Fluent API in Entity Framework, the .ToTable() method is used to specify the database ___________ for an entity.
- Index
- Name
- Schema
- Structure
In Entity Framework, the .ToTable() method within the Fluent API is employed to designate the name of the database table for a specific entity, ensuring proper mapping between entities and tables.
The ___________ method of a Dataset saves changes made to its data back to the database.
- ApplyChanges
- Commit
- SubmitChanges
- Update
The ApplyChanges method of a Dataset saves changes made to its data back to the database. This method is typically used in disconnected scenarios where changes made to the dataset need to be synchronized with the underlying database.
The ADO.NET connection pool can be affected by factors such as ___________ and ___________.
- Connection string; Timeout settings
- Data encryption; Authentication
- Firewall configuration; Server location
- Network latency; Database load
The ADO.NET connection pool's performance can be influenced by factors like network latency, which affects the time taken to establish connections, and database load, which determines the availability of connections in the pool.
The AcceptChanges method is typically called after ___________.
- Deleting data
- Inserting data
- Retrieving data
- Updating data
The AcceptChanges method is commonly used after updating data in ADO.NET to commit changes to the underlying data source and clear the change tracking mechanism.
The DeleteOnSubmit method is used to mark an entity for ___________.
- Deletion
- Updating
- Insertion
- Deletion or Removal
The correct option is 'Deletion or Removal'. The DeleteOnSubmit method in LINQ to SQL is used to mark an entity for deletion. It does not immediately delete the entity from the database but rather flags it for deletion. The actual deletion occurs when the SubmitChanges method is called on the DataContext. This method is commonly used to prepare objects for deletion before committing changes to the database.