噸sql中從2個表

Question

刪除重複行我有2個表：

• FirstTable
• SecondTable

FirstTable具有這些列

sales_ID varchar(250) 
product_ID int 

SecondTable具有這些列

sales_ID varchar(250) 
product_ID int 
CreateDate datetime 

如果FirstTable的sales_ID和product_ID匹配SecondTable的sales_Id和product_ID，並且如果SecondTable的CreatedDate是2015年4月7日，我需要從SecondTable

我試過這樣刪除的行：

delete from SecondTable 
WHERE sales_Id IN (SELECT sales_Id FROM FirstTable) 
    and product_ID IN (SELECT product_ID FROM FirstTable) 
    and CreatedDate = '07-04-2015' 

但是，它刪除所有行，並且它根據我想要的不正確（不工作）查詢。

如果product_ID等於product_ID和sales_ID等於sales_ID並且CreatedDate等於07.04.2015等於SecondTable，如何刪除重複行？

希望你明白我的壞英文

謝謝。

Answer 1

試試這個：

delete from secondtable 
from secondTable st 
inner join firstTable ft on st.sales_id = ft.sales_id 
    and st.product_id = ft.product_id 
    and st.CreatedDate = '2015-07-04' 

注意您可能會想換行上述交易，以確保你不刪除不需要的記錄 - 或將陳述變爲選擇：

select st.* 
from secondTable st 
inner join firstTable ft on st.sales_id = ft.sales_id 
    and st.product_id = ft.product_id 
    and st.CreatedDate = '2015-07-04' 

Answer 2

這是因爲它純粹檢查第二張表和產品ID中是否存在銷售ID，而不是相同的記錄。

嘗試例如

Delete T2 
FROM firsttable AS T1 
INNER JOIN secondtable T2 
on T1.sales_id = T2.sales_id 
AND T1.product_id = T2.product_id 
WHERE T1.CreatedDate = '20150407' -- assuming you mean 7th April? 

Answer 3

DELETE 
    FROM SecondTable t2 
    JOIN FirstTable t1 
    ON t1.sales_ID = t2.sales_ID 
    AND t1.product_ID = t2.product_ID 
    AND t1.CreatedDate = '2015-07-04'