mysql - 将先前的值与 mysql 中的当前值相加

Question

我有两列，即zone和total_bill_amount，我想将以前的值与列的当前值相加。我已经使用了

 select  zone, total_bill_amount, sum(total_bill_amount) as Total_Bill
 from Cal_Amount  
 where cluster_number = 'clust 2' 
 group by zone,total_bill_amount;

 1. zone       total_bill_amount   Total_Bill                           

 2. ABC          45                    45                               

 3. PQR          78                    123                              

 4. XYZ          16                    139

45 = 45 45+78 = 123 123 + 16 = 139

Answer 1

您可以使用变量来做到这一点:

select zone, total_bill_amount,
       @total := @total + total_bill_amount AS Total_Bill
from Cal_Amount
where cluster_number = 'clust 2'        
cross join (select @total := 0) as var
order by zone

您必须用指定表中顺序的列替换 zone，以防 zone 不是该列。