PostgreSQL Hero
@postgresqlhero.bsky.social
ARRAY_AGG is one of those functions you wish you knew about sooner
December 5, 2025 at 9:47 AM
ARRAY_AGG is one of those functions you wish you knew about sooner
Timezones in SQL be like
December 5, 2025 at 9:41 AM
Timezones in SQL be like
This is why we have backups. You have backups, right?
December 5, 2025 at 9:37 AM
This is why we have backups. You have backups, right?
When you give AI database access
December 5, 2025 at 9:36 AM
When you give AI database access
FUN FACT: https://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 🐘
No server. No backend. Just WASM magic under 3MB.
Learn SQL for free without us paying a cent for infrastructure 🐘
December 5, 2025 at 9:27 AM
FUN FACT: https://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 🐘
No server. No backend. Just WASM magic under 3MB.
Learn SQL for free without us paying a cent for infrastructure 🐘
One simple trick to speed up your queries 👇
December 4, 2025 at 10:48 PM
One simple trick to speed up your queries 👇
Every MySQL user eventually...
December 4, 2025 at 10:45 PM
Every MySQL user eventually...
PostgreSQL fans be like 🐘
December 4, 2025 at 10:44 PM
PostgreSQL fans be like 🐘
Top N per group? LATERAL JOIN.
The most underrated SQL feature.
The most underrated SQL feature.
December 4, 2025 at 10:42 PM
Top N per group? LATERAL JOIN.
The most underrated SQL feature.
The most underrated SQL feature.
Division by zero? NULLIF handles it.
Returns NULL instead of crashing.
Returns NULL instead of crashing.
December 4, 2025 at 10:41 PM
Division by zero? NULLIF handles it.
Returns NULL instead of crashing.
Returns NULL instead of crashing.
Subqueries are unreadable.
CTEs are not. Use WITH.
CTEs are not. Use WITH.
December 4, 2025 at 10:41 PM
Subqueries are unreadable.
CTEs are not. Use WITH.
CTEs are not. Use WITH.
Need a comma-separated list from SQL?
STRING_AGG. No app code needed.
STRING_AGG. No app code needed.
December 4, 2025 at 10:41 PM
Need a comma-separated list from SQL?
STRING_AGG. No app code needed.
STRING_AGG. No app code needed.
INSERT or UPDATE? Both.
ON CONFLICT DO UPDATE = upsert in one atomic query.
ON CONFLICT DO UPDATE = upsert in one atomic query.
December 4, 2025 at 10:41 PM
INSERT or UPDATE? Both.
ON CONFLICT DO UPDATE = upsert in one atomic query.
ON CONFLICT DO UPDATE = upsert in one atomic query.
Need a list of dates? Don't loop.
generate_series() is your friend.
generate_series() is your friend.
December 4, 2025 at 10:41 PM
Need a list of dates? Don't loop.
generate_series() is your friend.
generate_series() is your friend.
COUNT with conditions? Use FILTER.
One query. Multiple counts. No subqueries.
One query. Multiple counts. No subqueries.
December 4, 2025 at 10:41 PM
COUNT with conditions? Use FILTER.
One query. Multiple counts. No subqueries.
One query. Multiple counts. No subqueries.
INSERT and get the ID back. One query.
Stop doing 2 round trips to your database.
Stop doing 2 round trips to your database.
December 4, 2025 at 10:40 PM
INSERT and get the ID back. One query.
Stop doing 2 round trips to your database.
Stop doing 2 round trips to your database.
PostgreSQL's secret weapon: DISTINCT ON
Get the latest row per group in one query. No window functions needed.
Get the latest row per group in one query. No window functions needed.
December 4, 2025 at 10:40 PM
PostgreSQL's secret weapon: DISTINCT ON
Get the latest row per group in one query. No window functions needed.
Get the latest row per group in one query. No window functions needed.
Stop writing CASE WHEN for null checks.
COALESCE exists.
COALESCE exists.
December 4, 2025 at 10:40 PM
Stop writing CASE WHEN for null checks.
COALESCE exists.
COALESCE exists.