根据google BigQuery SQL中的属性删除重复行答案

【问题标题】：Remove duplicate rows according to the attribute in google BigQuery SQL根据google BigQuery SQL中的属性删除重复行
【发布时间】：2017-05-09 09:04:20
【问题描述】：

我有一张表叫：结果我正在使用 BigQuery 从 GA 中选择数据

SELECT
  Date,
  totals.pageviews,
  h.transaction.transactionId,
  h.item.itemQuantity,
  h.transaction.transactionRevenue,
  totals.bounces,
  fullvisitorid,
  totals.timeOnSite,
  device.browser,
  device.deviceCategory,
  trafficSource.source,
  channelGrouping,
  h.page.pagePath,
  h.eventInfo.eventCategory,
  device.operatingSystem
FROM
  `atomic-life-148403.126959513.ga_sessions_*`,
  UNNEST(hits) AS h
WHERE
  _TABLE_SUFFIX BETWEEN REPLACE(CAST(DATE_ADD(CURRENT_DATE(), INTERVAL -1 YEAR) AS STRING), '-','')
  AND CONCAT('intraday_', REPLACE(CAST(DATE_ADD(CURRENT_DATE(), INTERVAL 0 DAY) AS STRING), '-',''))
  ORDER BY
  date  DESC

有一些记录重复。如何从表中删除重复记录？

我想得到以下结果。

【问题讨论】：

您确实想查找并删除行，或者只是将它们从查询结果中隐藏？如果是后者，请使用 DISTINCT。如果是前者，它会变得更复杂一些。
如何只选择不同的行？因为 itemquentity 和收入是分开的

标签： sql google-bigquery

【解决方案1】：

您可以使用 ROW_NUMBER

WITH CTE AS 
(SELECT *, ROW_NUMBER() OVER (PARTITION BY transactionid ORDER BY 
transactionid) ROW FROM [YourTable]) 

DELETE [YourTable] 
FROM [YourTable]
JOIN CTE ON [YourTable].transactionid ON CTE.transactionid
                              WHERE CTE.ROW > 1

【讨论】：

【解决方案2】：

你可以使用ROW_NUMBER()这样的解析函数

select * from (
select *,
ROW_NUMBER() OVER(PARTITION BY transactionid ORDER BY transactionid) rownum
from result ) xxx
where rownum = 1;

【讨论】：

【解决方案3】：

以下是 BigQuery 标准 SQL

#standardSQL
SELECT DISTINCT
  Date,
  totals.pageviews,
  h.transaction.transactionId,
  h.item.itemQuantity,
  h.transaction.transactionRevenue,
  totals.bounces,
  fullvisitorid,
  totals.timeOnSite,
  device.browser,
  device.deviceCategory,
  trafficSource.source,
  channelGrouping,
  h.page.pagePath,
  h.eventInfo.eventCategory,
  device.operatingSystem
FROM
  `atomic-life-148403.126959513.ga_sessions_*`,
  UNNEST(hits) AS h
WHERE
  _TABLE_SUFFIX BETWEEN REPLACE(CAST(DATE_ADD(CURRENT_DATE(), INTERVAL -1 YEAR) AS STRING), '-','')
  AND CONCAT('intraday_', REPLACE(CAST(DATE_ADD(CURRENT_DATE(), INTERVAL 0 DAY) AS STRING), '-',''))
  ORDER BY
  date  DESC

如您所见 - 我刚刚将 DISTINCT 添加到您的 SELECT 中 - 详细了解 BigQuery 标准 SQL 的 SELECT and its modifiers

【讨论】：

【解决方案4】：

您可以选择唯一的行并删除其他行：

DELETE FROM MyTable
LEFT OUTER JOIN (
   SELECT DISTINCT * FROM MyTable
) as UniqueRows ON
   MyTable.KeyField= UniqueRows.KeyField
WHERE
   UniqueRows.KeyField IS NULL;

【讨论】：

【解决方案5】：

对所有选定的列使用 GROUP BY 应该可以消除结果中任何真正的重复行：

SELECT
  Date,
  totals.pageviews,
  h.transaction.transactionId,
  h.item.itemQuantity,
  h.transaction.transactionRevenue,
  totals.bounces,
  fullvisitorid,
  totals.timeOnSite,
  device.browser,
  device.deviceCategory,
  trafficSource.source,
  channelGrouping,
  h.page.pagePath,
  h.eventInfo.eventCategory,
  device.operatingSystem
FROM
  `atomic-life-148403.126959513.ga_sessions_*`,
  UNNEST(hits) AS h
WHERE
  _TABLE_SUFFIX BETWEEN REPLACE(CAST(DATE_ADD(CURRENT_DATE(), INTERVAL -1 
YEAR) AS STRING), '-','')
  AND CONCAT('intraday_', REPLACE(CAST(DATE_ADD(CURRENT_DATE(), INTERVAL 0 DAY) AS STRING), '-',''))
GROUP BY
  Date,
  totals.pageviews,
  h.transaction.transactionId,
  h.item.itemQuantity,
  h.transaction.transactionRevenue,
  totals.bounces,
  fullvisitorid,
  totals.timeOnSite,
  device.browser,
  device.deviceCategory,
  trafficSource.source,
  channelGrouping,
  h.page.pagePath,
  h.eventInfo.eventCategory,
  device.operatingSystem
ORDER BY
  date  DESC;

【讨论】：