JDBC

JDBC Connection Flow

1. Load driver (Class.forName)
2. Establish connection (DriverManager.getConnection)
3. Create PreparedStatement
4. Execute query
5. Process ResultSet
6. Close resources (try-with-resources)

JDBC Example

try (Connection conn = DriverManager.getConnection(url, user, pass);
     PreparedStatement stmt = conn.prepareStatement(
         "SELECT * FROM products WHERE id = ?")) {
    stmt.setLong(1, 123L);
    ResultSet rs = stmt.executeQuery();
    while (rs.next()) {
        String name = rs.getString("name");
    }
}

PreparedStatement vs Statement

Feature	Statement	PreparedStatement
SQL injection	Vulnerable	Protected
Performance	Slower	Faster (pre-compiled)

Design Principles

• Normalize to 3NF, denormalize for performance
• Use appropriate data types
• Add indexes for frequent queries
• Implement proper constraints

Query Optimization

• Use EXPLAIN ANALYZE
• Avoid SELECT *
• Use JOIN instead of subqueries
• Implement pagination

Operations

• Regular backups
• Monitor slow queries
• Implement connection pooling
• Use read replicas for scaling

Key Points

• Understanding JDBC is essential for production systems
• Always consider scalability and maintainability
• Test thoroughly before deploying to production
• Monitor performance and set up alerting

Common Patterns

1. Validation: Always validate input at the boundary
2. Error Handling: Use structured error responses
3. Logging: Log key events for debugging
4. Testing: Unit, integration, and load tests
5. Documentation: Keep docs updated with code changes