在一次选择特定值时排除电子邮件列表

Question

我试图在1个SELECT查询中做两件事（我知道我可以分两步完成这个但我想避免中间表）：

1. 从TABLE＆＃39; anothertable＆＃39;中选择特定值（仅限M和W - 可能还有其他值，但我只想要这些值而不是其他值）。
2. 避免选择退出和退回电子邮件（11k行，<5列）。

我不确定语法是否正确，因为查询是永远加载的。但是，大小不应该是一个问题（27k行，<5列和2个核心处理器）。

BEGIN

CREATE TABLE `mytable` AS (

SELECT * FROM `anothertable` A

WHERE NOT EXISTS (SELECT Email FROM `optout` B WHERE B.Email = A.Email)
AND NOT EXISTS (SELECT Email FROM `allbounced` C WHERE C.emailbounced = A.Email)

GROUP BY Email
HAVING 
(SUM(CASE WHEN target = 'M' THEN 1 ELSE 0 END) > 0 OR   -- MAN  is present
SUM(CASE WHEN target = 'W' THEN 1 ELSE 0 END) > 0 AND   -- WOMAN  is present
SUM(CASE WHEN target NOT IN ('M', 'W') THEN 1 ELSE 0 END) = 0)  -- only MAN or WOMAN

);

END

Answer 1

如果可能，您应该使用NOT IN代替NOT EXISTS。这应该更快：

BEGIN

CREATE TABLE `mytable` AS (

SELECT Email FROM `anothertable` A
WHERE Email NOT IN (SELECT Email FROM `optout`)
AND Email NOT IN (SELECT emailbounced FROM `allbounced`)

GROUP BY Email
HAVING 
(SUM(CASE WHEN target = 'M' THEN 1 ELSE 0 END) > 0 OR   -- MAN  is present
SUM(CASE WHEN target = 'W' THEN 1 ELSE 0 END) > 0 AND   -- WOMAN  is present
SUM(CASE WHEN target NOT IN ('M', 'W') THEN 1 ELSE 0 END) = 0)  -- only MAN or WOMAN

);

END