PostgreSQL SyntaxLesson 35Free preview

PostgreSQL CROSS JOIN

This lesson is part of PostgreSQL · All levels

Summary

CROSS JOIN results in a Cartesian time result of any possible pair of rows from two tables without any join condition. The number of rows results is a multiple of the number of rows of the second table. In addition to writing CROSS JOIN, PostgreSQL also recognizes a comma style that implicitly does the same thing.

Key points

Cross JOIN results in all combinations of the two-line pairs of tables.
The number of rows resulting is equal to the multiplication of the number of rows in the second table.
No need for an ON clause because it has no match conditions.
It can be written in commas between tables without the word "cross".

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