只返回数据库中的重复记录


Return only repeated records from database

我只需要返回数据库中重复了30次的行。我在SELECT之后添加了这个COUNT函数,但老实说,我不知道下一步该怎么做。有人能给我建议吗?

$variable = "SELECT COUNT(mail.h_datetime, sent.f_mail_subject, sent.f_mail_content)"
        ."FROM mail"
        ."INNER JOIN sent ON mail.h_id = sent.e_mail_templates_id"
        ."WHERE f_template_type =  'newsletter'";

对所有选定行执行GROUP BY。使用HAVING仅返回至少出现30次的行。

SELECT mail.h_datetime, sent.f_mail_subject, sent.f_mail_content
FROM mail
    INNER JOIN sent ON mail.h_id = sent.e_mail_templates_id
WHERE f_template_type =  'newsletter'
GROUP BY mail.h_datetime, sent.f_mail_subject, sent.f_mail_content
HAVING COUNT(*) >= 30