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PostgreSQL Hero

@postgresqlhero.bsky.social

280 followers 2.1K following 281 posts

Want to learn about PostgreSQL? You are in the good place! 🔗 postgresqlhero.alexisbouchez.com

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PostgreSQL Hero @postgresqlhero.bsky.social · 05/12/2025

ARRAY_AGG is one of those functions you wish you knew about sooner

SQL code showing ARRAY_AGG to collect tags into an array

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PostgreSQL Hero @postgresqlhero.bsky.social · 05/12/2025

Timezones in SQL be like

Meme: Clock with Roman numerals in wrong positions representing SQL timestamp confusion

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PostgreSQL Hero @postgresqlhero.bsky.social · 05/12/2025

This is why we have backups. You have backups, right?

Meme: Raccoon firing a golden machine gun with text 'When you're an intern but have prod access (everyone else quit)'

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PostgreSQL Hero @postgresqlhero.bsky.social · 05/12/2025

When you give AI database access

$Meme: Robot with ChatGPT logo saying 'You're absolutely right\!' when asked why it deleted the prod database$

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PostgreSQL Hero @postgresqlhero.bsky.social · 05/12/2025

FUN FACT: postgresqlhero.vercel.app runs a full PostgreSQL database directly in your browser using PGlite. No server. No backend. Just WASM magic under 3MB. Learn SQL for free without us paying a cent for infrastructure 🐘

PGlite homepage - Embeddable Postgres in WebAssembly

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PostgreSQL Hero @postgresqlhero.bsky.social · 04/12/2025

One simple trick to speed up your queries 👇

SQL code: DELETE FROM bad_habits WHERE type = using IN with subqueries

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PostgreSQL Hero @postgresqlhero.bsky.social · 04/12/2025

Every MySQL user eventually...

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PostgreSQL Hero @postgresqlhero.bsky.social · 04/12/2025

PostgreSQL fans be like 🐘

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PostgreSQL Hero @postgresqlhero.bsky.social · 04/12/2025

Top N per group? LATERAL JOIN. The most underrated SQL feature.

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PostgreSQL Hero @postgresqlhero.bsky.social · 04/12/2025

Division by zero? NULLIF handles it. Returns NULL instead of crashing.

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PostgreSQL Hero @postgresqlhero.bsky.social · 04/12/2025

Subqueries are unreadable. CTEs are not. Use WITH.

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PostgreSQL Hero @postgresqlhero.bsky.social · 04/12/2025

Need a comma-separated list from SQL? STRING_AGG. No app code needed.

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PostgreSQL Hero @postgresqlhero.bsky.social · 04/12/2025

INSERT or UPDATE? Both. ON CONFLICT DO UPDATE = upsert in one atomic query.

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PostgreSQL Hero @postgresqlhero.bsky.social · 04/12/2025

Need a list of dates? Don't loop. generate_series() is your friend.

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PostgreSQL Hero @postgresqlhero.bsky.social · 04/12/2025

COUNT with conditions? Use FILTER. One query. Multiple counts. No subqueries.

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PostgreSQL Hero @postgresqlhero.bsky.social · 04/12/2025

INSERT and get the ID back. One query. Stop doing 2 round trips to your database.

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PostgreSQL Hero @postgresqlhero.bsky.social · 04/12/2025

PostgreSQL's secret weapon: DISTINCT ON Get the latest row per group in one query. No window functions needed.

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PostgreSQL Hero @postgresqlhero.bsky.social · 04/12/2025

Stop writing CASE WHEN for null checks. COALESCE exists.

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