Big Query多个表

Question

我正在尝试从Google的BigQuery中的多个表中进行查询。 我在表'weather.stations'中找不到错误“Field'w.max_temperature'。”

这是我的SQL：

SELECT w.station_number, s.LAT, s.LON, w.year, w.month, avg(w.mean_temp) as [mean temp], max(w.max_temperature) as [max temp], min(w.min_temperature) as [min temp], avg(w.mean_visibility) as [avg visbility] FROM [weather.stations] s, [publicdata:samples.gsod] w WHERE w.station_number=s.USAF AND w.wban_number=s.WBAN GROUP BY w.month, w.year, w.station_number, s.LAT, s.LON;

我试图将“max_temperature”引用到[publicdata：samples.gsod]，但无论出于何种原因，它都将它引用到[weather.stations]。 有任何想法吗？ 谢谢！

Answer 1

听起来你正在尝试进行JOIN，但是在BigQuery SQL中，以逗号分隔的表列表表示UNION ALL而不是JOIN（是的，它很奇怪;是的，如果可以，我们可能会更改它，但是在这一点上可能为时已晚）。

你最想要的是：

SELECT w.station_number, s.LAT, s.LON, w.year, w.month, 
       avg(w.mean_temp) as [mean temp], max(w.max_temperature) as [max temp], 
       min(w.min_temperature) as [min temp], 
       avg(w.mean_visibility) as [avg visbility]
FROM [weather.stations] s, 
JOIN [publicdata:samples.gsod] w
ON w.station_number=s.USAF AND w.wban_number=s.WBAN 
GROUP BY w.month, w.year, w.station_number, s.LAT, s.LON;