无论如何在结果显示时连接选择查询列吗？

Question

比如我有一个查询：

select item_name, day, month, year from some_table; 

，但我想结果表为2列，而不是4，这样的：

[Item name][Date (dd.mm.YYYY)]

我们能做到这一点？

我使用Google的Biq Query标准SQL。

Answer 1

下面是BigQuery的标准SQL

#standardSQL 
SELECT item_name, DATE(year, month, day) AS date 
FROM `yourTable` 

您可以测试/使用下面的虚拟数据

#standardSQL 
WITH `yourTable` AS (
    SELECT 'abc' AS item_name, 5 AS day, 10 AS month, 2017 AS year UNION ALL 
    SELECT 'xyz', 1, 9, 2017 
) 
SELECT item_name, DATE(year, month, day) AS date 
FROM `yourTable` 

Answer 2

使用此查询

select item_name, CONCAT(cast(day as STRING)) ,'.' ,cast(month as STRING), '.',cast(year as STRING)) as Date 

Answer 3

您可以使用CONCAT

查询

select item_name, concat(day, '.', month, '.', year) as date 
from some_table; 

如果列是整数类型，那么你必须将其转换为字符串。

select item_name, 
concat(cast(day as string), '.', cast(month as string), '.', cast(year as string)) as date 
from some_table;