php - 错误 SET SQL_BIG_SELECTS=1 或 SET MAX_JOIN_SIZE=#

Question

我的查询遇到了问题......

SELECT 
keywords.keyword,
keywords.keyid,
sources.s_title,
sources.s_disc,
sources.s_link,
sources.sourceid,
sources.s_link
FROM link_ks
INNER JOIN keywords ON link_ks.keyid = keywords.keyid
INNER JOIN sources ON link_ks.sourceid = sources.sourceid
INNER JOIN thumbsup_items ON link_ks.sourceid = thumbsup_items.name
WHERE link_ks.keyid = :keyid 
order by thumbsup_items.votes_up desc,thumbsup_items.votes_down asc,(thumbsup_items.votes_up+thumbsup_items.votes_down) desc

当数据库很小的时候一切都很好但是随着数据库变大我得到这个错误

 The SELECT would examine more than MAX_JOIN_SIZE rows; check your WHERE and use SET
 SQL_BIG_SELECTS=1 or SET MAX_JOIN_SIZE=# if the SELECT is okay

但是当我删除

 order by thumbsup_items.votes_up desc,thumbsup_items.votes_down asc,
(thumbsup_items.votes_up+thumbsup_items.votes_down) desc

问题得到解决......但是order by对于这个查询很重要......

有没有其他方法可以编写这个查询或者我该如何解决这个问题？？

Answer 1

那个MAX_JOIN_SIZE 和 SQL_BIG_SELECTS 不会让您运行会挂起服务器的长查询。

在运行查询之前使用它:

 SET OPTION SQL_BIG_SELECTS = 1

或者使用这个:

SET SQL_BIG_SELECTS=1

chek this