根据列值合并具有不同日期的两个表?

时间:2019-01-03 18:03:29

标签: sql google-bigquery union

我们在1月1日切换到新平台,我需要合并两个表以获取包含旧数据和新数据的数据源。但是,某些帐户必须在1月1日之前转出旧平台。

新数据表具有所有帐户12月的数据,但我只想使用没有旧12月数据的新12月数据。如何将新数据与从1月1日开始的大多数帐户数据以及从12月适当的一天开始的异常帐户合并在一起?

例如:对于Account1,我需要从1月1日开始的新数据;对于Account2,我需要12月30日以后的新数据;对于帐户3,我需要12月31日以后的新数据

Old Table  
------------------------------------   
Account         Date         Sales  
------------------------------------
Account1        12-29-18     10  
Account1        12-30-18     10  
Account1        12-31-18     5  
Account2        12-29-18     10    
Account3        12-29-18     20  
Account3        12-30-18     10

New Table
------------------------------------   
Account         Date         Sales  
------------------------------------
Account1        12-29-18     10  
Account1        12-30-18     10  
Account1        12-31-18     5  
Account1        01-01-19     20  
Account2        12-30-18     15  
Account2        12-31-18     20  
Account2        01-01-19     10  
Account3        12-30-18     10  
Account3        12-31-18     20  
Account3        01-01-19     5  

Output
------------------------------------   
Account         Date         Sales  
------------------------------------
Account1        12-29-18     10  
Account1        12-30-18     10  
Account1        12-31-18     5  
Account1        01-01-19     20  
Account2        12-29-18     10
Account2        12-30-18     15  
Account2        12-31-18     20  
Account2        01-01-19     10
Account3        12-29-18     20  
Account3        12-30-18     10
Account3        12-31-18     20  
Account3        01-01-19     5  

1 个答案:

答案 0 :(得分:1)

以下是用于BigQuery标准SQL

  #standardSQL
  SELECT account, date, 
    ARRAY_AGG(sales ORDER BY data LIMIT 1)[OFFSET(0)] sales
  FROM (
    SELECT 'old' data, * FROM `project.dataset.old_table` UNION ALL 
    SELECT 'new' data, * FROM `project.dataset.new_table` 
  )
  GROUP BY account, date

您可以使用问题中的示例数据作为

进行测试和操作
  #standardSQL
  WITH `project.dataset.old_table` AS (
    SELECT 'Account1' account, '12-29-18' date, 10 sales UNION ALL  
    SELECT 'Account1', '12-30-18', 10 UNION ALL  
    SELECT 'Account1', '12-31-18', 5 UNION ALL  
    SELECT 'Account2', '12-29-18', 10 UNION ALL    
    SELECT 'Account3', '12-29-18', 20 UNION ALL  
    SELECT 'Account3', '12-30-18', 10 
  ),  `project.dataset.new_table` AS (
    SELECT 'Account1' account, '12-29-18' date, 10 sales UNION ALL
    SELECT 'Account1', '12-30-18', 10 UNION ALL
    SELECT 'Account1', '12-31-18', 5 UNION ALL
    SELECT 'Account1', '01-01-19', 20 UNION ALL
    SELECT 'Account2', '12-30-18', 15 UNION ALL
    SELECT 'Account2', '12-31-18', 20 UNION ALL
    SELECT 'Account2', '01-01-19', 10 UNION ALL
    SELECT 'Account3', '12-30-18', 10 UNION ALL
    SELECT 'Account3', '12-31-18', 20 UNION ALL
    SELECT 'Account3', '01-01-19', 5 
  )
  SELECT account, date, 
    ARRAY_AGG(sales ORDER BY data LIMIT 1)[OFFSET(0)] sales
  FROM (
    SELECT 'old' data, * FROM `project.dataset.old_table` UNION ALL 
    SELECT 'new' data, * FROM `project.dataset.new_table` 
  )
  GROUP BY account, date
  ORDER BY account, PARSE_DATE('%m-%d-%y', date) 

有结果

Row account     date        sales    
1   Account1    12-29-18    10   
2   Account1    12-30-18    10   
3   Account1    12-31-18    5    
4   Account1    01-01-19    20   
5   Account2    12-29-18    10   
6   Account2    12-30-18    15   
7   Account2    12-31-18    20   
8   Account2    01-01-19    10   
9   Account3    12-29-18    20   
10  Account3    12-30-18    10   
11  Account3    12-31-18    20   
12  Account3    01-01-19    5    
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