Comment 1:

What SQL datatype represents a time.Duration ?

Comment 2 by raul.san@sent.com:

+ Oracle implements SQL92's INTERVAL DAY TO SECOND
+ Mysql has TIME
+ PostreSQL has the INTERVAL
+ SQLite3 doesn't support any kind of time fields (datetime, time,
interval), but accepts all as legal types so could be used INTEGER.

Comment 3 by raul.san@sent.com:

SQLite3 in SQLAlchemy was implemented using a string with SQL datatype "TEXT":
https://bitbucket.org/sqlalchemy/sqlalchemy/src/02615a0fde68f339969c806460462ca1fd5a98f2/lib/sqlalchemy/dialects/sqlite/base.py?at=default#cl-309
There was a discussion in Django forums about its implementation in Django's ORM:
https://groups.google.com/forum/?hl=en&fromgroups=#!topic/django-developers/0yMWznlk268

Comment 4:

As I mentioned in a github issue (https://github.com/bmizerany/pq/issues/78) for the pq
driver I don't think this is possible for Postgres. The interval datatype is a 12-byte
value with a much larger range than time.Duration:
http://www.postgresql.org/docs/9.2/static/datatype-datetime.html
It seems Oracle's interval type supports up to 9 digits in the days field, which is also
larger than time.Duration (290 years is ~105920 days)
MySQL is more limited, the range is +/- 839 hours.

Comment 5 by raul.san@sent.com:

Then, since time.Duration is an int64
(http://golang.org/src/pkg/time/time.go?s=12544:12563#L374), could be used a SQL
datatype to store an int64:
+ BIGINT in MySQL
+ bigint in PostgreSQL
+ INTEGER in SQLite3

Comment 6:

If you need a custom type, you can implement sql.Scanner and driver.Valuer.
I would like to keep the database/sql and database/sql/driver packages how they are.

Status changed to WontFix.