Mysql的一列基於其他列

Question

什麼是MySQL查詢來從表下面的結果值添加值？在金額欄中添加應根據invoiceID進行。

Answer 1

SELECT @rownum := @rownum + 1 AS ID, InvoiceID, SUM(AMOUNT) 
FROM <tablename>, (SELECT @rownum := 0) r 
GROUP BY InvoiceID 

Answer 2

試試這個：

select @i:=@i+1 AS id,a.* 
    from 
    (select InvoiceID,sum(Amount) as Amount 
     from your_table 
     group by InvoiceID)a,(SELECT @i:=0) r 

SQL Fiddel demo

Answer 3

select ID,InvoiceID, SUM(Amount) 
from <table> 
group by InvoiceID