BigQuery: "Invalid function name"

Question

In BigQuery, I ran this query

SELECT SEC_TO_TIMESTAMP(start_time), resource
FROM [logs.requestlogs_20140305]

and received the error

Error: Invalid function name: SEC_TO_TIMESTAMP

SEC_TO_TIMESTAMP is listed in the date functions reference, so why does this error come up?

Answer 1

Turns out my start_time column was of type float, not an integer which SEC_TO_TIMESTAMP expects. Changing the query to

SELECT SEC_TO_TIMESTAMP(INTEGER(start_time)), resource
FROM [logs.requestlogs_20140305]

fixed the problem.