Question

I’m working with a large transaction data set and would like to group a count of individual customer transactions by month. I am unable to use the timestamp function in the GROUP BY and return the following error:

BAD_QUERY (expression STRFTIME_UTC_USEC([DATESTART], ‘%b’) in GROUP BY is invalid)

Is there a simple workaround to achieve this or should I build a calendar table (which may be the simplest option)?

Answer 1

You have to use an alias:

SELECT STRFTIME_UTC_USEC(DATESTART, '%b') as month, COUNT(TRANSACTION)
FROM datasetId.tableId
GROUP BY month