在数据库中列出匹配的记录和不匹配的记录

Question

我有一个查询将检查表中的无效发票，然后检查同一张表 以查看无效发票是否重新提交。我想知道的是...有没有方法 添加一列以查看如果无效发票不重新招标，并在列中列为“N”..

这里是我当前的查询：

SELECT  t1.Store_Number, t1.Invoice_Number, t1.Invoice_Date, t1.Vehicle_Tag, t1.Void_Reason, t1.Void_Employee_Tax_Payer_Id, t1.Invoice_Total, t1.Void_Flag, 
         t2.Invoice_Number AS Expr1, t2.Vehicle_Tag AS Expr2, t2.Invoice_Total AS Expr3 
FROM   Invoice_Tb AS t1 INNER JOIN 
         Invoice_Tb AS t2 ON t1.Vehicle_Tag = t2.Vehicle_Tag 
WHERE  (t1.Void_Flag = 'y') AND (t1.Invoice_Date BETWEEN CONVERT(DATETIME, '2012-08-01 00:00:00', 102) AND CONVERT(DATETIME, '2012-08-02 00:00:00', 102)) AND 
         (t2.Void_Flag = 'n') AND (t2.Invoice_Date BETWEEN CONVERT(DATETIME, '2012-08-01 00:00:00', 102) AND CONVERT(DATETIME, '2012-08-02 00:00:00', 102)) 

这里是我的电流输出：

Store Number Invoice Number Date Plate Number Void Reason Employee Invoice Amount Voided New Invoice Number Plate Number New Invoice Amount Re-Tendered 
1568 3257714 8/1/2012 0:00 BBY1234 WRONG PRICE ENTERED 89556532 21.39 3257714 BBY1234 26.74 Y 

的我想什么例子：比方说，发票＃123失效，从来没有重新招标......我想要 显示上面的内容并添加一个列标题“重新标记”并列出“n”，其中一个invo冰不是 重新招标。输出将类似于此：

Store Number Invoice Number Date Plate Number Void Reason Employee Invoice Amount Voided New Invoice Number Plate Number New Invoice Amount Re-Tendered 
1568 3257714 8/1/2012 0:00 BBY1234 WRONG PRICE ENTERED 89556532 21.39 3257714 BBY1234 26.74 Y 
1552 123 8/1/2012 0:00 Dwb0534 Wrong Plate number 73215654 15.95    N 

Answer 1

你需要一个左连接

SELECT  t1.Store_Number, t1.Invoice_Number, t1.Invoice_Date, t1.Vehicle_Tag, t1.Void_Reason, t1.Void_Employee_Tax_Payer_Id, t1.Invoice_Total, t1.Void_Flag, 
         t2.Invoice_Number AS Expr1, t2.Vehicle_Tag AS Expr2, t2.Invoice_Total AS Expr3, case when t2.Vehicle_Tag is null then 'n' else 'y' end as retendered 
FROM   Invoice_Tb AS t1 LEFT JOIN 
         Invoice_Tb AS t2 ON t1.Vehicle_Tag = t2.Vehicle_Tag And 
         (t2.Void_Flag = 'n') AND (t2.Invoice_Date BETWEEN CONVERT(DATETIME, '2012-08-01 00:00:00', 102) AND CONVERT(DATETIME, '2012-08-02 00:00:00', 102)) 
WHERE  (t1.Void_Flag = 'y') AND (t1.Invoice_Date BETWEEN CONVERT(DATETIME, '2012-08-01 00:00:00', 102) AND CONVERT(DATETIME, '2012-08-02 00:00:00', 102))