呵呵,,,有个坑,,mysql默认不支持full join 是吧. 什么是full join呢就是left+right join 可以使用union联表解决这个问题
union 链接 http://www.php20.com/forum.php?m ... &extra=page%3D1
原表链接 http://www.php20.com/forum.php?m ... &extra=page%3D1咱们的链接如下
[SQL]
纯文本查看
复制代码
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select
b.title,b.content,a.class_name,a.id
as
classid
from
news_class
as
a
left
join
news
as
b
on
a.id=b.id
union
all
select
b.title,b.content,a.class_name,a.id
as
classid
from
news_class
as
a
right
join
news
as
b
on
a.id=b.id;
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结果right和left 的合一块去了. 所以出现了重复内容