Bigquery suggest me ‘EXTRACT’ funtion syntax:
extract(datetime_part FROM timestamp_expr [AT TIME ZONE tz_spec])
However, Bigquery notice “Unexpected keyword AT”. Moreover, it’s syntax in official Bigquery document is totally different.
Similar case with ‘Date’ function. Can anyone explain this? What should i fill in syntax is suggested by BQ? Does have any similar cases? Thanks you!!
An clear explaination.
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The allowed syntax depends on whether the operand is a DATE, a DATETIME or a TIMESTAMP.
EXTRACT function
For a TIMESTAMP:
EXTRACT(part FROM timestamp_expression [AT TIME ZONE time_zone])
https://cloud.google.com/bigquery/docs/reference/standard-sql/timestamp_functions#extract
For a DATE or DATETIME:
EXTRACT(part FROM date_expression)
https://cloud.google.com/bigquery/docs/reference/standard-sql/date_functions#extract
DATE function
For a TIMESTAMP:
DATE(timestamp_expression [, time_zone_expression])
https://cloud.google.com/bigquery/docs/reference/standard-sql/date_functions#date
(It’s a bit confusing that they have this under “date functions” and not “timestamp functions”, because while the result is a date, the function is applied on a timestamp and should hence be put in that chapter.)
For a DATETIME:
DATE(datetime_expression)
https://cloud.google.com/bigquery/docs/reference/standard-sql/date_functions#date
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