Self Joins and Hierarchies/Pair records from the same day

Generate pairs of rows that share a date.

Section: Self joins

Pair records from the same day

sql
sql
SELECT a.id, b.id, a.event_date
FROM events a
JOIN events b
  ON a.event_date = b.event_date
 AND a.id < b.id;
Explanation

Useful for pairing or clash detection inside one table.

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Compare similar commands or jump into common fixes when this command is part of a bigger troubleshooting path.

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