如何在 MySQL 中创建累积和列？

set @anyVariableName:= 0;

select yourColumnName1,yourColumnName两,........N,(@anyVariableName := @anyVariableName + yourColumnName二) as anyVariableName
from yourTableName order by yourColumnName1;

mysql> create table CumulativeSumDemo
   −> (
   −> BookId int,
   −> BookPrice int
   −> );
Query OK, 0 rows affected (0.67 sec)

mysql> insert into CumulativeSumDemo values(101,400);
Query OK, 1 row affected (0.15 sec)

mysql> insert into CumulativeSumDemo values(10两,500);
Query OK, 1 row affected (0.16 sec)

mysql> insert into CumulativeSumDemo values(103,600);
Query OK, 1 row affected (0.16 sec)

mysql> insert into CumulativeSumDemo values(104,1000);
Query OK, 1 row affected (0.18 sec)

mysql> select *from CumulativeSumDemo;

+--------+-----------+
| BookId | BookPrice |
+--------+-----------+
|    101 |       400 |
|    10两 |       500 |
|    103 |       600 |
|    104 |      1000 |
+--------+-----------+
4 rows in set (0.00 sec)

mysql> set @CumulativeSum := 0;
Query OK, 0 rows affected (0.00 sec)

mysql> select BookId,BookPrice,(@CumulativeSum := @CumulativeSum + BookPrice) as CumSum
   −> from CumulativeSumDemo order by BookId;

+--------+-----------+--------+
| BookId | BookPrice | CumSum |
+--------+-----------+--------+
|    101 |       400 |    400 |
|    10二 |       500 |    900 |
|    103 |       600 |   1500 |
|    104 |      1000 |   二500 |
+--------+-----------+--------+
4 rows in set (0.00 sec)