Date Part Constants

Additional Date Parts Extracting Multiple Parts CURRENT_TIMESTAMP with EXTRACT This query extracts the current hour and classifies the time of day. The pattern is useful for dashboards that display time-aware greetings or adjust behavior based on business hours. Extracting DOW (day of week) is useful for detecting whether demand differs between weekdays and weekends. Grouping by DOW across a full year reveals structural patterns in consumer behavior.

About This Interactive Section

This section is part of the Dates: Intermediate lesson on DataDriven, a free data engineering interview prep platform. Each section includes explanations, worked examples, and hands-on code challenges that execute in real time. SQL queries run against a live PostgreSQL database. Python runs in a sandboxed Docker container. Data modeling problems validate against interactive schema canvases. All content is framed around what data engineering interviewers actually test at companies like Meta, Google, Amazon, Netflix, Stripe, and Databricks.

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