Question

我有一个看起来像这样的联接：

LEFT JOIN abc__emails.my208 my3 
   ON my3.eid = my.eid 
   AND (
         my3.my_id = 417 
         AND my3.data = 'AB Deleted Account'
   )

此查询是bordeline runnable。我试图保存每一块内存。我的问题是：

LEFT JOIN abc__emails.my208 my3 
   ON my3.eid = my.eid 
   AND my3.data = 'AB Deleted Account'

我删除了my3.my_id = 417部分。

记录my_id = 417包括＆＃39; AB已删除帐户＆＃39;还有其他几个字符串。我把它包括在内是因为我认为我可以帮助SQL缩小范围。这是错的吗？

我真的只想让联接成为my3.data = 'AB Deleted Account'.

的记录

最好添加尽可能多的＆＃34;过滤器＆＃34;尽可能多地删除？

eid已经成为两个牌桌上的关键。

以下反馈是EXPLAIN的输出

1   SIMPLE  co  ALL                 198784  Using temporary; Using filesort
1   SIMPLE  my  eq_ref  PRIMARY PRIMARY 8   abc_emails.co.id,const  1   
1   SIMPLE  my1 eq_ref  PRIMARY PRIMARY 8   abc_emails.my.eid,const 1   
1   SIMPLE  my2 eq_ref  PRIMARY PRIMARY 8   abc_emails.my.eid,const 1   
1   SIMPLE  my3 ref ver_eid ver_eid 4   abc_emails.my.eid   246 
1   SIMPLE  i   ref eid_iid eid_iid 10  abc_emails.my.eid,const 1   Using where; Using index
1   SIMPLE  nvk eq_ref  PRIMARY PRIMARY 4   abc_emails.co.id    1

以下是查询本身

SELECT
    co.id AS ID_Eid,
    co.email,
    def.def_medium AS def_Medium_def208,
    co.created AS Contact_Create_Date,
    my1.data AS PAW_ID,
    my.data AS Trial_Date,
    my2.data AS Upgrade_Date,
    MIN(my3.lastmod) AS Cancel_Date
FROM 
    abc_emails.cid208 co
LEFT JOIN abc_emails.my208 my ON my.eid = co.id AND my.my_id = 581
LEFT JOIN abc_emails.my208 my1 ON my1.eid = my.eid AND my1.my_id = 2765 
LEFT JOIN abc_emails.my208 my2 ON my2.eid = my.eid AND my2.my_id = 3347 
LEFT JOIN abc__emails.my208 my3 ON my3.eid = my.eid AND (my3.my_id = 417 AND my3.data = 'AB Deleted Account') 
LEFT JOIN abc_emails.i208 i ON i.eid = my.eid AND i.iid = 22467
LEFT JOIN abc_emails.def208 def ON def.eid = co.id
WHERE i.iid IS NULL
GROUP BY ID_Eid, email, def_Medium_def208, Contact_Create_Date, PAW_ID, Upgrade_Date

优化加入

0 个答案: