I am facing this error:
BIGQUERRY SELECT list expression references column CHANNEL_ID which is neither grouped nor aggregated at [10:13]
I dont know why it's caused,Can someone explain it to me? Here are my codes:
SELECT t0.CHANNEL_ID, t1.CHANNEL_DISPLAY_NAME FROM ( SELECT TIMESTAMP_TRUNC(_PARTITIONTIME, MONTH) as `DATE`, CHANNEL_ID FROM `pops-204909.yt_kids.p_content_owner_basic_a3_yt_kids` WHERE DATE(_PARTITIONTIME) between "2017-08-01" and "2017-08-31" GROUP BY `DATE` ) t0 LEFT JOIN ( SELECT TIMESTAMP_TRUNC(_PARTITIONTIME, MONTH) as `DATE`, CHANNEL_DISPLAY_NAME FROM `pops-204909.yt_kids.p_content_owner_ad_revenue_raw_a1_yt_kids` WHERE DATE(_PARTITIONTIME) between "2017-08-01" and "2017-08-31" GROUP BY `DATE` ) t1 on t0.DATE = t1.DATE
When you use
GROUP BY - all expressions in the respective SELECT list must be either those which are in the GROUP BY or should be with AGGREGATION function - like MIN, MAX etc. See more about GROUP BY clause
So in your case both sub-queries are missing respectively CHANNEL_ID and CHANNEL_DISPLAY_NAME in the respective GROUP BY. Or depends on your logic they should come with some aggregation function.
Note: Above explains the error you see. Rather than this - you query makes no much sense to me even if you will fix that specific error - but I hope you have something in mind :o)