该查询可以正常工作,但执行时间过长。它在xampp localhost上运行。此SQL查询是否有优化?
只是我想选择webpage.id其中字=“财产以后”和字 =“另一个财产以后”
我的意思是,如果你在谷歌搜索,你可以使用快捷键 “蟒蛇! - 猫“ 这意味着获得所有包含单词”python“而不包含单词”cat“的链接。
SELECT webpage.title, word.title, word.id, webpage.title, webpage.id, webpage.link, wordpage.wordID, wordpage.id, wordpage.type, wordpage.pageID
FROM SE_word AS word
INNER JOIN se_wordpage AS wordpage ON wordpage.wordID = word.id
INNER JOIN se_webpage AS webpage ON wordpage.pageID = webpage.id
WHERE word.title = "python"
AND webpage.id NOT IN (
SELECT WP.id
FROM se_webpage AS WP
INNER JOIN se_wordpage AS WOP ON WP.id = WOP.pageID
INNER JOIN se_word AS W ON W.id = WOP.wordID
WHERE W.title = "cat"
)
GROUP BY webpage.id
ORDER BY webpage.title DESC
它例如
table se_Word is
**id | title**
1 | "game"
2 | "java"
3 | "python"
table se_WebPage is
**id | title**
1 | "www.ABCDEF.com"
2 | "www.ABCDR.net"
3 | "www.ABC.com"
table se_WordPage is
**id | pageID | wordID**
1 | 1 | 1
2 | 2 | 3
3 | 3 | 3
3 | 2 | 1
结果简单的搜索引擎应该webpage.id = 3
here is创建脚本 是否有任何优化?
在此先感谢。
1.使用'EXPLAIN'提供执行计划2.提供所有表模式 – zerkms
我已经添加了它。谢谢 –
@Strawberry你的意思是子查询? 我认为主要查询中列的值不同于你没有添加的子查询 –