What is the main purpose of using try-catch blocks in database operations?
- To close connections
- To create databases
- To execute SQL queries
- To handle exceptions
The main purpose of using try-catch blocks in database operations is to handle exceptions that may occur during the execution of SQL queries or other database-related operations.
Which method is used to retrieve detailed information about an SQL exception?
- getErrorCode()
- getMessage()
- getSQLException()
- getSQLState()
The getErrorCode() method is used to retrieve the specific error code associated with an SQL exception, providing detailed information about the exception.
How can you handle a situation where a database connection is lost during a transaction?
- Commit the transaction
- Ignore the issue and proceed
- Retry the transaction
- Rollback the transaction
If a database connection is lost during a transaction, you can handle it by retrying the transaction, allowing for the re-establishment of the connection and completion of the operation.
What is the significance of the finally block in JDBC operations?
- To handle exceptions
- To improve performance
- To optimize code execution
- To release resources
The finally block in JDBC operations is significant for releasing resources, ensuring that resources like database connections are properly closed, regardless of whether an exception occurs.
How do you differentiate between checked and unchecked SQL exceptions?
- Checked exceptions are SQLExceptions
- Checked exceptions are caught at compile-time
- Unchecked exceptions are SQLExceptions
- Unchecked exceptions are caught at compile-time
Checked SQL exceptions are those derived from SQLException, and they must be either caught or declared to be thrown. Unchecked SQL exceptions are those that extend RuntimeException.
What is the best practice for handling SQL exceptions in a multi-tier application?
- Catch and log the exception at the point of occurrence
- Convert the SQL exception to a custom exception
- Handle the exception and continue processing
- Propagate the exception to the upper tiers
The best practice is to propagate the SQL exception to the upper tiers to allow centralized handling and logging, providing a clear separation of concerns in a multi-tier application.
In JDBC, how can you ensure that all resources are freed, even if an SQL exception occurs?
- Close resources in the catch block
- Implement a custom resource management mechanism
- Resources are automatically freed in JDBC
- Use the finally block to close resources
Using the finally block ensures that resources (like connections, statements, result sets) are closed, even if an SQL exception occurs, promoting proper resource management and avoiding leaks.
In JDBC, the __________ exception is thrown when there is a problem with the SQL syntax.
- DBException
- SQLException
- SQLSyntaxException
- SyntaxException
In JDBC, the SQLException is thrown when there is a problem with the SQL syntax.
The _________ method is used to retrieve cookies from the request object.
- findCookies()
- getCookies()
- requestCookies()
- retrieveCookies()
The getCookies() method is used to retrieve cookies from the request object in a servlet.
To ensure that database resources are always released, use the __________ block to close connections.
- catch
- finally
- release
- try
To ensure that database resources are always released, use the finally block to close connections.