是否存在任何差异,主要是在使用多个表之间的性能方面:
SELECT widgets.* FROM widgets, manufacturers
WHERE widgets.manufacturer_id = manufacturers.id
AND manufacturers.location = 2
和JOIN
ing:
SELECT widgets.* FROM widgets
JOIN manufacturers ON widgets.manufacturer_id = manufacturers.id
WHERE manufacturers.location = 2
我特别询问MySQL / MariaDB是否有任何区别。