Java Programming - MCQ Practice Questions

SQLException is thrown when database-related errors occur, including connection failures and SQL execution errors.

executeQuery() returns a ResultSet containing the rows fetched from the database for SELECT queries.

PreparedStatement is used for parameterized queries with placeholders (?), which prevents SQL injection by separating SQL logic from data.

The correct JDBC connection sequence is: Class.forName() → DriverManager.getConnection() → Create Statement → Execute Query → Close resources.

setAutoCommit(false) disables auto-commit mode, allowing manual control over transactions through commit() and rollback() methods.

addBatch() and executeBatch() methods allow multiple SQL statements to be grouped and executed together, reducing network traffic and improving performance.

When Class.forName() cannot locate the driver class, it throws ClassNotFoundException, indicating the driver JAR is not in the classpath.

commit() permanently saves all changes made during the transaction, while rollback() discards all changes and reverts to the previous state.

The Statement interface is used to execute SQL queries. Connection creates the statement, Driver manages connections, and DataSource provides connection pooling, but Statement is the actual executor.