id,node_id,number,title,user,state,locked,assignee,milestone,comments,created_at,updated_at,closed_at,author_association,pull_request,body,repo,type,active_lock_reason,performed_via_github_app,reactions,draft,state_reason
1553425465,I_kwDOCGYnMM5cl2Q5,522,Add COLUMN_TYPE_MAPPING for timedelta,81377,closed,0,,,0,2023-01-23T16:49:54Z,2023-11-04T00:49:51Z,2023-11-04T00:49:51Z,NONE,,"Currently trying to create a column with Python type `datetime.timedelta` results in an error:

```
>>> from sqlite_utils import Database
>>> db = Database(""test.db"")
>>> test_tbl = db['test']
>>> test_tbl.insert({'col1': datetime.timedelta()})
Traceback (most recent call last):
  File ""<stdin>"", line 1, in <module>
  File ""/usr/local/lib/python3.10/dist-packages/sqlite_utils/db.py"", line 2979, in insert
    return self.insert_all(
  File ""/usr/local/lib/python3.10/dist-packages/sqlite_utils/db.py"", line 3082, in insert_all
    self.create(
  File ""/usr/local/lib/python3.10/dist-packages/sqlite_utils/db.py"", line 1574, in create
    self.db.create_table(
  File ""/usr/local/lib/python3.10/dist-packages/sqlite_utils/db.py"", line 961, in create_table
    sql = self.create_table_sql(
  File ""/usr/local/lib/python3.10/dist-packages/sqlite_utils/db.py"", line 852, in create_table_sql
    column_type=COLUMN_TYPE_MAPPING[column_type],
KeyError: <class 'datetime.timedelta'>
```

The reason this would be useful is that `MySQLdb` uses `timedelta` for MySQL `TIME` columns:

```
>>> import MySQLdb
>>> conn = MySQLdb.connect(host='database', user='user', passwd='pw')
>>> csr = conn.cursor()
>>> csr.execute(""SELECT CAST('11:20' AS TIME)"")
>>> tuple(csr)
((datetime.timedelta(seconds=40800),),)
```

So currently any attempt to convert a MySQL DB with a `TIME` column using `db-to-sqlite` will result in the above error.

I was rather surprised that `MySQLdb` uses `timedelta` for `TIME` columns but I see that [this column type](https://dev.mysql.com/doc/refman/8.0/en/time.html) is intended for time intervals as well as the time of day so it makes sense. 

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