SQL练习 - ythy/blog GitHub Wiki

实例1

COMPANY_CODE    INVOICE_NO    IMA_INVOICE_NO
 XXX             XXX           XXX 
 XXX             XXX           XXX 

COMPANY_CODE相同的前提下,INVOICE_NO的每个值与IMA_INVOICE_NO列都比较一遍, 然后把有这种重复的INVOICE_NO返回

SQL：

select distinct(x1) 
from  (  select  b1.INVOICE_NO x1, b2.IMA_INVOICE_NO y2
         from dodacst b1
         left join dodacst b2 on b1.COMPANY_CODE=b2.COMPANY_CODE  and b1.INVOICE_NO = b2.IMA_INVOICE_NO  
                   and b1.rowid != b2.rowid 
      ) 
where y2 is not null