使用2个不同的代码选择重复记录搜索的语句

Question

我正在尝试在SQL中编写一个select语句，该语句将在数据库中搜索具有2个单独代码的重复记录。换句话说，伪代码将是

选择m_code = J或T的发票编号。这样可以给我发票号码2345两次，一次是代码J，一次是代码T.

Answer 1

如果您正在寻找特定代码，那么您可以使用带有HAVING和GROUP BY的WHERE子句过滤器：

select invoice
from yourtable
where m_code in ('J', 'T')
group by invoice
having count(distinct m_code) > 1;

但是如果您想要使用任何两个重复的m_codes返回和发票，那么您可以使用：

select invoice
from yourtable
group by invoice
having count(distinct m_code) > 1;

查看两个查询的SQL Fiddle with Demo

Answer 2

Select invoice_numbers,COUNT(DISTINCT m_code) as CNT
FROM TABLE where m_code in('J','T')
GROUP BY invoice_numbers
HAVING CNT >1;

<强> FIDDLE