相关疑难解决方法(0)

为简单起见,假设所有相关字段都是NOT NULL.

你可以做:

SELECT
    table1.this, table2.that, table2.somethingelse
FROM
    table1, table2
WHERE
    table1.foreignkey = table2.primarykey
    AND (some other conditions)

要不然:

SELECT
    table1.this, table2.that, table2.somethingelse
FROM
    table1 INNER JOIN table2
    ON table1.foreignkey = table2.primarykey
WHERE
    (some other conditions)

这两个是以同样的方式工作MySQL吗？

考虑我们有两个表,Users和Posts.user_id是Posts表中的外键,是表中的主键Users.

这两个sql查询之间有什么区别？

select user.name, post.title 
  from users as user, posts as post 
 where post.user_id = user.user_id;

与

select user.name, post.title 
  from users as user join posts as post using user_id;