Bigquery查找条目所属的表

Question

我正在清理我的生产数据集，我正在寻找一些无用的条目。

SELECT count(pid_like) FROM TABLE_DATE_RANGE(DATASET.TABLE_PRODUCTION_, DATE_ADD(CURRENT_TIMESTAMP(), -30, 'DAY'),CURRENT_TIMESTAMP()) where c1 is null and c2 is null and c3 is null and c4 is null 

所以我想删除其中C1，C2，C3和C4空条目。

之前，我在最后30桌清洁为由：

# done for each last 30 tables 
DELETE FROM DATASET.TABLE_PRODUCTION_YYYYMMDD where c1 is null and c2 is null and c2 is null and c4 is null. 

但清洗后，一些无用的条目将会保留，但我不能对他们是什么台找到。

Answer 1

试试这个发现哪些表行与空值：

#standardSQL 
SELECT 
    _TABLE_SUFFIX AS suffix, 
    COUNT(*) AS null_count 
FROM `DATASET.TABLE_PRODUCTION_*` 
WHERE _TABLE_SUFFIX BETWEEN 
    FORMAT_DATE('%Y%m%d', DATE_SUB(CURRENT_DATE(), INTERVAL 30 DAY)) AND 
    FORMAT_DATE('%Y%m%d', CURRENT_DATE()) AND 
    c1 IS NULL AND 
    c2 IS NULL AND 
    c3 IS NULL AND 
    c4 IS NULL 
GROUP BY suffix 
HAVING null_count > 0 
ORDER BY null_count DESC; 

它将与空行和计数返回后缀（日期）。