AS aliases for columns

Aliases let you create readable, descriptive names for columns and tables without changing the underlying data. When you use an alias, the underlying table and its data remain unchanged. The alias only affects how the data is labeled in your query and results. Toggle between the examples below to see each type. Practical Aliasing Production databases often have column names like usr_cre_dt or prc_usd_base that save keystrokes when engineers build the schema but confuse everyone reading queries later. Aliasing them to created_at or base_price costs one extra word per column and turns your output into something any teammate can read at a glance without consulting the data dictionary. Practice: Column Aliases Column aliases are especially valuable in reports and dashboards where the raw colum

About This Interactive Section

This section is part of the Query Structure: Beginner 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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