如何将旧版SQL BigQuery转换为标准SQL?

时间:2018-09-27 12:48:32

标签: google-bigquery standard-sql legacy-sql

我一直在尝试将旧版SQL BigQuery代码转换为标准SQL,但我不断收到大量错误。

这是原始旧版SQL:

    SELECT t.page_path,
        t.second_page_path,
        t.third_page_path,
        t.fourth_page_path,
        CONCAT(t.page_path,IF(t.second_page_path IS NULL,"","-"),
        IFNULL(t.second_page_path,""),IF(t.third_page_path IS NULL,"","-"),
        IFNULL(t.third_page_path,""),IF(t.fourth_page_path IS NULL,"","-"),
        IFNULL(t.fourth_page_path,"")) AS full_page_journey,
        count(sessionId) AS total_sessions

FROM (

SELECT
     CONCAT(fullVisitorId,"-",STRING(visitStartTime)) AS sessionId,
     hits.hitNumber,
     hits.page.pagePath AS page_path,
     LEAD(hits.page.pagePath) OVER (PARTITION BY fullVisitorId, visitStartTime ORDER BY hits.hitNumber) AS second_page_path,
     LEAD(hits.page.pagePath,2) OVER (PARTITION BY fullVisitorId, visitStartTime ORDER BY hits.hitNumber) AS third_page_path,
     LEAD(hits.page.pagePath,3) OVER (PARTITION BY fullVisitorId, visitStartTime ORDER BY hits.hitNumber) AS fourth_page_path
   FROM
    TABLE_DATE_RANGE( [xxxxxxx:xxxxxxx.ga_sessions_],
TIMESTAMP('2017-01-01'), TIMESTAMP('2017-01-02') )
   WHERE
     hits.type="PAGE"

     ) t
     WHERE t.hits.hitNumber=1
     GROUP BY t.page_path,
              t.second_page_path,
              t.third_page_path,
              t.fourth_page_path,
              full_page_journey
     ORDER BY total_sessions DESC

更新(已编辑):这是到目前为止我能做的:

    SELECT t.page_path,
        t.second_page_path,
        t.third_page_path,
        t.fourth_page_path,
        CONCAT(t.page_path,IF(t.second_page_path IS NULL,"","-"),
        IFNULL(t.second_page_path,""),IF(t.third_page_path IS NULL,"","-"),
        IFNULL(t.third_page_path,""),IF(t.fourth_page_path IS NULL,"","-"),
        IFNULL(t.fourth_page_path,"")) AS full_page_journey,
        count(sessionId) AS total_sessions

FROM (

SELECT
     CONCAT(fullVisitorId,"-",cast(visitStartTime as string)) AS sessionId,
     hits.hitNumber,
     hits.page.pagePath AS page_path,
     LEAD(hits.page.pagePath) OVER (PARTITION BY fullVisitorId, visitStartTime ORDER BY hits.hitNumber) AS second_page_path,
     LEAD(hits.page.pagePath,2) OVER (PARTITION BY fullVisitorId, visitStartTime ORDER BY hits.hitNumber) AS third_page_path,
     LEAD(hits.page.pagePath,3) OVER (PARTITION BY fullVisitorId, visitStartTime ORDER BY hits.hitNumber) AS fourth_page_path
   FROM
       `xxxxxxxxxxx.xxxxxxx.ga_sessions_*`,
        UNNEST(hits) AS hits
     WHERE
          _TABLE_SUFFIX BETWEEN 
          FORMAT_DATE('%Y%m%d', DATE_ADD(CURRENT_DATE(), INTERVAL -16 DAY))AND 
          FORMAT_DATE('%Y%m%d', DATE_ADD(CURRENT_DATE(), INTERVAL -1 DAY))AND
          hits.type = 'PAGE' ) AS t
          WHERE t.hits.hitNumber = 1
     GROUP BY t.page_path,
              t.second_page_path,
              t.third_page_path,
              t.fourth_page_path,
              full_page_journey
     ORDER BY total_sessions DESC

如果有人可以帮助您找出语法错误的地方,那就太好了。

一些错误包括:

  

无法访问类型为ARRAY的值的字段hitNumber      

出现“ _TABLE_SUFFIX”问题,该问题与通配符有关。

1 个答案:

答案 0 :(得分:3)

作为起点,DATE_ADD需要一个日期,但是您给它提供了时间戳,而_TABLE_SUFFIX需要一个字符串,但是给了它一个日期(有点)。

尝试在现有语法周围使用CURRENT_DATE()和FORMAT_DATE:

 FORMAT_DATE('%Y%m%d', DATE_ADD(CURRENT_DATE(), INTERVAL -16 DAY))

此问题可能对hitNumber错误有用:

query-hits-and-custom-dimensions-in-the-bigquery

请尝试使用CTE而不是子查询,因为这样可以使事情更清晰,更容易调试。

WITH CTE AS 
(SELECT
  CONCAT(fullVisitorId,"-",cast(visitStartTime as string)) AS sessionId,
  hits.hitNumber as hitNumber,
  hits.page.pagePath AS page_path,
  LEAD(hits.page.pagePath) OVER (PARTITION BY fullVisitorId, visitStartTime     
ORDER BY hits.hitNumber) AS second_page_path, 
LEAD(hits.page.pagePath,2) OVER (PARTITION BY fullVisitorId, visitStartTime
ORDER BY hits.hitNumber) AS third_page_path,
  LEAD(hits.page.pagePath,3) OVER (PARTITION BY fullVisitorId,
  visitStartTime ORDER BY hits.hitNumber) AS fourth_page_path
FROM
 `xxxxxxxxxxx.xxxxxxx.ga_sessions_*`,
  UNNEST(hits) AS hits
WHERE
  _TABLE_SUFFIX BETWEEN 
  FORMAT_DATE('%Y%m%d', DATE_ADD(CURRENT_DATE(), INTERVAL -16 DAY))AND 
  FORMAT_DATE('%Y%m%d', DATE_ADD(CURRENT_DATE(), INTERVAL -1 DAY))AND
  hits.type = 'PAGE' )

SELECT page_path,
  second_page_path,
  third_page_path,
  fourth_page_path,
  CONCAT(page_path,IF(second_page_path IS NULL,"","-"),
  IFNULL(second_page_path,""),IF(third_page_path IS NULL,"","-"),
  IFNULL(third_page_path,""),IF(fourth_page_path IS NULL,"","-"),
  IFNULL(fourth_page_path,"")) AS full_page_journey,
  count(sessionId) AS total_sessions
FROM CTE
WHERE hitNumber = 1
GROUP BY page_path,
    second_page_path,
    third_page_path,
    fourth_page_path,
    full_page_journey
ORDER BY total_sessions DESC