Select from таблица 1, таблица 2 - какая левая, какая правая?

In SQL, when using the JOIN operator, if you write SELECT ... FROM table1 LEFT JOIN table2, then table1 is the left table, and table2 is the right table.

That is, the left table is the one that comes before the JOIN keyword, and the right table is the one after.

For example:

SELECT * FROM table1 LEFT JOIN table2 ON table1.id = table2.id

Here, table1 is the left table, and table2 is the right table.

This is important because with LEFT JOIN, all rows from the left table are preserved, and from the right table only those that match the condition; the others will be NULL.