wrong results with extract(second from <interval>)

[gregrahn]

What happens?

When extracting the seconds component from an interval it returns the entire value in seconds. This is what extract(epoch from <interval>) should return.

To Reproduce

D select extract( second from interval '2 hours 2 minutes 10 seconds' ) as value_should_be_10;
┌────────────────────┐
│ value_should_be_10 │
├────────────────────┤
│ 7330               │
└────────────────────┘

D select extract( epoch from interval '2 hours 2 minutes 10 seconds' ) as value_should_be_7330;
┌──────────────────────┐
│ value_should_be_7330 │
├──────────────────────┤
│ 7330                 │
└──────────────────────┘

Environment (please complete the following information):

• OS: macOS 11.5.2
• DuckDB Version: 0.3.0
• DuckDB Client: duckdb-cli

Before Submitting

• Have you tried this on the latest master branch?

No, but it's also incorrect in the test file here as well
https://github.com/duckdb/duckdb/blob/master/test/sql/function/interval/test_extract.test#L126

PostgreSQL 13.2

greg.rahn=# SELECT i, EXTRACT(second FROM i) FROM intervals;
       i       | date_part
---------------+-----------
 2 years       |         0
 1 year 4 mons |         0
 42 days       |         0
 00:34:26.3434 |   26.3434
 [NULL]        |    [NULL]

DuckDB

D SELECT i, EXTRACT(second FROM i) FROM intervals;
┌─────────────────┬──────────────────────┐
│        i        │ date_part(second, i) │
├─────────────────┼──────────────────────┤
│ 2 years         │ 0                    │
│ 1 year 4 months │ 0                    │
│ 42 days         │ 0                    │
│ 00:34:26.3434   │ 2066                 │ <<< should be 20.3434
│                 │                      │
└─────────────────┴──────────────────────┘

[Mytherin]

Thanks for the report! Going to have a look at this.