Question

我有两个不同的表，我希望将uniques视为单个表的位置。表结构是相同的。我尝试了UNION，UNION DISTINCT，SELECT DISTINCT with a UNION以及各种各样的事情。但我仍然得到重复和东西。

是否可以获得唯一的电子邮件地址以及其他数据

SELECT DISTINCT email_address, first_name, last_name,
    street_address, city, postal_code, province, created_date
FROM entries
WHERE subscribe='1'

从一张桌子上得到它。

注意，如果我只是想要电子邮件地址，UNION会工作。但是当我添加其他数据时，它就不再做任何事了。

Answer 1

试试这个

SELECT email_address, first_name, last_name,
    street_address, city, postal_code, province, created_date
FROM 
    (SELECT * FROM entries WHERE subscribe='1'
    UNION
    SELECT * FROM entries2 WHERE subscribe='1') AS tmp
GROUP BY email_address

Answer 2

    (SELECT /*Fields*/ FROM entries e1)
    UNION
    (SELECT /*same Fields*/ FROM entries2 e2)
    WHERE subscribe=1
    GROUP BY email_address

MySQL从两个不同的表中选择uniques？

2 个答案: