Answer by Fast Engy for How to do an update + join in PostgreSQL?

For those actually wanting to do a JOIN you can also use:

UPDATE aSET price = b_alias.unit_priceFROM      a AS a_aliasLEFT JOIN b AS b_alias ON a_alias.b_fk = b_alias.idWHERE a_alias.unit_name LIKE 'some_value'AND a.id = a_alias.id;

You can use the a_alias in the SET section on the right of the equals sign if needed.The fields on the left of the equals sign don't require a table reference as they are deemed to be from the original "a" table.