Impala SQL 将多个值合并为 1

Posted 2023-03-22

【中文标题】Impala SQL 将多个值合并为 1

【英文标题】：Combine multiple value into 1 for Impala SQL

【发布时间】：2021-10-06 03:27:30

【问题描述】：

我想将多个产品条目合并为 1，并将它们的价格相加。目前，数据库如下所示：

Name                Product               Price
Zack                Vanilla Twist         1
Jane                Lolipop               0.5
Zack                Lolipop               0.5
Zack                Candymint             0.5
Jane                ChocoLoco LM          1.5

我想把它的外观改成这样：

Name                Product                                 sum(Price)
Zack                Vanilla Twist, Lolipop, Candymint       2
Jane                Lolipop, ChocoLoco LM                   2

如何使用 Impala SQL 做到这一点？

【参考方案1】：

此查询适用于 mysql，这可能会对您有所帮助。

select Name, group_concat(`product` separator ', ') Product, sum(Price)
from tempt
group by Name
order by Name desc

dbfiddle here

【讨论】：

Impala 中的语法会略有不同impala.apache.org/docs/build/html/topics/…

【参考方案2】：

declare @temp table (Name varchar(50), product varchar(50), Price decimal(3,1))
insert into @temp values ('Zack','Vanilla Twist',1)
insert into @temp values ('Jane','Lolipop',0.5)
insert into @temp values ('Zack','Lolipop',0.5)
insert into @temp values ('Zack','Candymint',0.5)
insert into @temp values ('Jane','ChocoLoco LM',1.5)

-- No cursor, Whil loop, or User defined function:
SELECT 
  Name,
  STUFF((
    SELECT ', ' + product 
    FROM @temp 
    WHERE (name = Results.name) 
    FOR XML PATH(''),TYPE).value('(./text())[1]','VARCHAR(MAX)')
  ,1,2,'') AS Product
  ,sum(Price) as [Sum(Price)]
FROM @temp Results
GROUP BY name

输出：

Name    Product                             Sum(Price)
Jane    Lolipop, ChocoLoco LM               2
Zack    Vanilla Twist, Lolipop, Candymint   2