相关疑难解决方法(0)

查询是否也这样做？标准是什么？

如果我改变其中一种写查询方式,我会失去性能吗？

查询1

   SELECT a.*, b.id AS b_id
     FROM table_a AS a
LEFT JOIN table_b AS b
       ON a.id = b.id

查询2

   SELECT a.*, b.id AS b_id
     FROM table_a a, table_b b
    WHERE a.id = b.id