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6 articles tagged #SQL.
P.01A data analyst is not a junior data scientist or a dashboard builder. What the role requires, how it differs, and the screen that finds decision-changing work.
P.02Pessimistic locking stops one request from starting; optimistic lets both run and catches the conflict at the end. How each works, with SQL, and how to pick.
P.03Soft delete sounds like the safe default, but it quietly breaks unique constraints, foreign keys, and query performance unless you design for it up front.
P.04dbt turns SQL SELECT statements into a tested, documented, version-controlled data pipeline. Here's how it works and when you should add it to your data stack.
P.05Running totals, rankings, moving averages, and lag comparisons without application loops or self-joins. How window functions actually work, in Postgres.
P.06EditorPickMaster SQL from basics to advanced — SELECT, JOIN, GROUP BY, ORDER BY, indexes, date functions, and more using SQLite with Python.