MySQL加入查询

Question

我遇到了MySQL连接查询的问题 - 不幸的是我对连接不太好。

Table page_section:
-------------------
id
page_id
name
display_order


Table page_section_sub:
-----------------------
id
page_section_id
page_id
content

一个page_section可以有很多page_section_sub

在我的页面上，我想显示page_section_sub命令的page_section.display_order

目前我有这个：

$query="SELECT * FROM page_section_sub WHERE page_section_id IN (1,2,3,4,5) 
ORDER BY display_order";

但这不起作用，因为它缺少连接。 我该怎么做呢？

Answer 1

select pss.*
from page_section_sub pss
inner join page_section ps on pss.page_section_id = ps.id
where pss.page_section_id in (1, 2, 3, 4, 5)
order by ps.display_order

Answer 2

试试这种方式：

SELECT * FROM page_section
LEFT JOIN page_section_sub ON page_section.page_id = page_section_sub.page_id
WHERE page_section_id IN (1,2,3,4,5) 
ORDER BY display_order;

Answer 3

尝试这个：

Select page_section_id.* from page_section_id natural join page_section 
WHERE page_section_id IN (1,2,3,4,5) order by page_section_id.display_order