SQL - 添加列值单表

Question

我有一张这样的桌子

Id|purchase_date | Purchase_price
1 |02-May-17     |$10.00
2 |02-May-17     |$20.00
3 |02-May-17     |$30.00

我想编写一个查询，其中所有purchase_price 的总和将根据purchase_date 计算。 有人可以建议查询吗？

Answer 1

你可以用 groupby 子句试试这个

select sum(replace(Purchase_price, '$', '')) as total from tbl group by purchase_date

Answer 2

使用 Mysql Replace 函数从价格中删除 $ 然后用户 SUM 后跟 group by 函数类似

SELECT SUM(REPLACE(Purchase_price,'$','')) AS price from tablename group by purchase_date

http://www.w3resource.com/mysql/string-functions/mysql-replace-function.php

Answer 3

假设你去动态货币符号

SELECT SUM(CAST(SUBSTR(Purchase_price, 2) as DECIMAL(4,2))) FROM tablename GROUP BY purchase_date;