Changing Schema in GBQ - sql

Question

I manually created a duration field in excel which calculates a time duration between a start date and end date and formatted it as HH:MM:SS. When I upload this in Google Big query it appears as a string. Then I used a CAST function
SELECT CAST (ride_length AS INTERVAL)
to change the type from STRING to INTERVAL and got the following error
Invalid INTERVAL value '0.00:22:28'
I need to change the data type to a number so I can calculate maximum, minimum, and average duration. GBQ doesn't let me do that with a string data type.
SELECT CAST (ride_length AS INTERVAL)

Answer 1

Can you try below:
WITH
sampleData AS(
SELECT
'01:05:07' AS duration
UNION ALL
SELECT
'02:05:07' AS duration
UNION ALL
SELECT
'04:05:07' AS duration ),
sample AS (
SELECT
CAST(duration AS TIME FORMAT 'HH24:MI:SS') AS duration2
FROM
sampleData --converts string to time format
)
SELECT
MAX(duration2) AS MAXTIME,
MIN(duration2) AS MINTIME,
TIME(
EXTRACT(hour FROM AVG(duration2 - '0:0:0')),
EXTRACT(minute FROM AVG(duration2 - '0:0:0')),
EXTRACT(second FROM AVG(duration2 - '0:0:0'))
) as AVERAGE from
sample;
This is given that your sample's format are accepted by BigQuery, See the sample output below for getting Max, Min, Average:
UPDATE:
Additional Code (for better readability, just change the names appropriate to your table ):
WITH sample AS (
SELECT
CAST(yourfieldName AS TIME FORMAT 'HH24:MI:SS') AS duration
FROM
yourTableId --converts string to time format
)
SELECT
MAX(duration) AS MAXTIME,
MIN(duration) AS MINTIME,
TIME(
EXTRACT(hour FROM AVG(duration - '0:0:0')),
EXTRACT(minute FROM AVG(duration - '0:0:0')),
EXTRACT(second FROM AVG(duration - '0:0:0'))
) as AVERAGE from
sample;