html_url,issue_url,id,node_id,user,user_label,created_at,updated_at,author_association,body,reactions,issue,issue_label,performed_via_github_app
https://github.com/simonw/sqlite-utils/issues/114#issuecomment-696500767,https://api.github.com/repos/simonw/sqlite-utils/issues/114,696500767,MDEyOklzc3VlQ29tbWVudDY5NjUwMDc2Nw==,9599,simonw,2020-09-22T04:21:45Z,2020-09-22T04:21:45Z,OWNER,Documentation: https://sqlite-utils.readthedocs.io/en/latest/python-api.html#transforming-a-table,"{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",621989740,table.transform() method for advanced alter table,
https://github.com/simonw/sqlite-utils/issues/114#issuecomment-696454485,https://api.github.com/repos/simonw/sqlite-utils/issues/114,696454485,MDEyOklzc3VlQ29tbWVudDY5NjQ1NDQ4NQ==,9599,simonw,2020-09-22T00:42:35Z,2020-09-22T00:42:35Z,OWNER,The reason I'm working on this now is that I'd like to support many more options for data cleanup in the Datasette ecosystem - so being able to do things like convert the type of existing columns becomes increasingly important.,"{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",621989740,table.transform() method for advanced alter table,
https://github.com/simonw/sqlite-utils/issues/114#issuecomment-696435194,https://api.github.com/repos/simonw/sqlite-utils/issues/114,696435194,MDEyOklzc3VlQ29tbWVudDY5NjQzNTE5NA==,9599,simonw,2020-09-21T23:34:14Z,2020-09-21T23:35:00Z,OWNER,"I think the fiddliest part of the implementation here is code that takes the existing `columns_dict` of the table and the incoming `columns=` and `drop=` and `rename=` parameters and produces the columns dictionary for the new table, ready to be fed to `.create_table()`.
This logic probably also needs to return a structure that can be used to build the `INSERT INTO ... SELECT ... FROM` query.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",621989740,table.transform() method for advanced alter table,
https://github.com/simonw/sqlite-utils/issues/114#issuecomment-696434638,https://api.github.com/repos/simonw/sqlite-utils/issues/114,696434638,MDEyOklzc3VlQ29tbWVudDY5NjQzNDYzOA==,9599,simonw,2020-09-21T23:32:26Z,2020-09-21T23:32:26Z,OWNER,A test that confirms that this mechanism can turn a `rowid` into a non-rowid table would be good too.,"{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",621989740,table.transform() method for advanced alter table,
https://github.com/simonw/sqlite-utils/issues/114#issuecomment-696434237,https://api.github.com/repos/simonw/sqlite-utils/issues/114,696434237,MDEyOklzc3VlQ29tbWVudDY5NjQzNDIzNw==,9599,simonw,2020-09-21T23:31:07Z,2020-09-21T23:31:57Z,OWNER,"Does it make sense to support the `pk=` argument for changing the primary key?
If the user requests a primary key that doesn't make sense I think an integrity error will be raised when the SQL is being executed, which should hopefully cancel the transaction and raise an error. Need to check that this is what happens.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",621989740,table.transform() method for advanced alter table,
https://github.com/simonw/sqlite-utils/issues/114#issuecomment-696434097,https://api.github.com/repos/simonw/sqlite-utils/issues/114,696434097,MDEyOklzc3VlQ29tbWVudDY5NjQzNDA5Nw==,9599,simonw,2020-09-21T23:30:40Z,2020-09-21T23:30:40Z,OWNER,"Since I have a `column_order=None` argument already, maybe I can ignore the order of the columns in that first argument and use that instead?","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",621989740,table.transform() method for advanced alter table,
https://github.com/simonw/sqlite-utils/issues/114#issuecomment-696433778,https://api.github.com/repos/simonw/sqlite-utils/issues/114,696433778,MDEyOklzc3VlQ29tbWVudDY5NjQzMzc3OA==,9599,simonw,2020-09-21T23:29:39Z,2020-09-21T23:29:39Z,OWNER,"The `columns=` argument is optional - so you can do just a rename operation like so:
```
table.transform(rename={""age"": ""dog_age""})
```","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",621989740,table.transform() method for advanced alter table,
https://github.com/simonw/sqlite-utils/issues/114#issuecomment-696433542,https://api.github.com/repos/simonw/sqlite-utils/issues/114,696433542,MDEyOklzc3VlQ29tbWVudDY5NjQzMzU0Mg==,9599,simonw,2020-09-21T23:28:58Z,2020-09-21T23:28:58Z,OWNER,"If you want to both change the type of a column AND rename it in the same operation, how would you do that? I think like this:
```python
table.transform({""age"": int}, rename={""age"": ""dog_age""})
```
So any rename logic is applied at the end, after the type transformation or re-ordering logic.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",621989740,table.transform() method for advanced alter table,
https://github.com/simonw/sqlite-utils/issues/114#issuecomment-696432690,https://api.github.com/repos/simonw/sqlite-utils/issues/114,696432690,MDEyOklzc3VlQ29tbWVudDY5NjQzMjY5MA==,9599,simonw,2020-09-21T23:26:32Z,2020-09-21T23:27:38Z,OWNER,"To expand on what that first argument - the `columns` argument - does. Say you have a table like this:
```
id integer
name text
age text
```
Any columns omitted from the `columns=` argument are left alone - they have to be explicitly dropped using `drop=` if you want to drop them.
Any new columns are added (at the end of the table):
```
table.tranform({""size"": float})
```
Any columns that have their type changed will have their type changed:
```
table.tranform({""age"": int})
```
Should I also re-order columns if the order doesn't match? I think so. Open question as to what happens to columns that aren't mentioned at all in the dictionary though - what order should they go in?","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",621989740,table.transform() method for advanced alter table,
https://github.com/simonw/sqlite-utils/issues/114#issuecomment-696431058,https://api.github.com/repos/simonw/sqlite-utils/issues/114,696431058,MDEyOklzc3VlQ29tbWVudDY5NjQzMTA1OA==,9599,simonw,2020-09-21T23:21:37Z,2020-09-21T23:21:37Z,OWNER,I may need to do something special for `rowid` tables to ensure that the `rowid` values in the transformed table match those from the old table.,"{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",621989740,table.transform() method for advanced alter table,
https://github.com/simonw/sqlite-utils/issues/114#issuecomment-696430843,https://api.github.com/repos/simonw/sqlite-utils/issues/114,696430843,MDEyOklzc3VlQ29tbWVudDY5NjQzMDg0Mw==,9599,simonw,2020-09-21T23:21:00Z,2020-09-21T23:21:00Z,OWNER,"For FTS tables associated with the table that is being transformed, should I automatically drop the old FTS table and recreate it against the new one or will it just magically continue to work after the table is renamed?","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",621989740,table.transform() method for advanced alter table,
https://github.com/simonw/sqlite-utils/issues/114#issuecomment-696423138,https://api.github.com/repos/simonw/sqlite-utils/issues/114,696423138,MDEyOklzc3VlQ29tbWVudDY5NjQyMzEzOA==,9599,simonw,2020-09-21T22:59:17Z,2020-09-21T23:01:06Z,OWNER,I'm going to sketch out a prototype of this new API design in that branch.,"{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",621989740,table.transform() method for advanced alter table,
https://github.com/simonw/sqlite-utils/issues/114#issuecomment-696423066,https://api.github.com/repos/simonw/sqlite-utils/issues/114,696423066,MDEyOklzc3VlQ29tbWVudDY5NjQyMzA2Ng==,9599,simonw,2020-09-21T22:59:01Z,2020-09-21T22:59:01Z,OWNER,"I'm rethinking the API design now. Maybe it could look like this:
To change the type of the `author_id` column from `text` to `int`:
```python
books.transform({""author_id"": int})
```
This would leave the existing columns alone, but would change the type of this column.
To rename `author_id` to `author_identifier`:
```python
books.transform(rename={""author_id"": ""author_identifier""})
```
To drop a column:
```python
books.transform(drop=[""author_id""])
```
Since the parameters all operate on columns they don't need to be called `drop_column` and `rename_column`.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",621989740,table.transform() method for advanced alter table,
https://github.com/simonw/sqlite-utils/issues/114#issuecomment-696421240,https://api.github.com/repos/simonw/sqlite-utils/issues/114,696421240,MDEyOklzc3VlQ29tbWVudDY5NjQyMTI0MA==,9599,simonw,2020-09-21T22:53:48Z,2020-09-21T22:53:48Z,OWNER,"I've decided to call this `table.transform()` - I was over-thinking whether people would remember that `.transform()` actually transforms the table, but that's what documentation is for.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",621989740,table.transform() method for advanced alter table,
https://github.com/simonw/sqlite-utils/issues/114#issuecomment-664106621,https://api.github.com/repos/simonw/sqlite-utils/issues/114,664106621,MDEyOklzc3VlQ29tbWVudDY2NDEwNjYyMQ==,9599,simonw,2020-07-27T04:01:13Z,2020-07-27T04:01:13Z,OWNER,Work in progress in `transform` branch here: https://github.com/simonw/sqlite-utils/tree/transform,"{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",621989740,table.transform() method for advanced alter table,
https://github.com/simonw/sqlite-utils/issues/114#issuecomment-656363548,https://api.github.com/repos/simonw/sqlite-utils/issues/114,656363548,MDEyOklzc3VlQ29tbWVudDY1NjM2MzU0OA==,9599,simonw,2020-07-09T21:37:28Z,2020-07-09T21:37:28Z,OWNER,"I'm going to add a second method `.transform_table_sql(...)` - which returns the SQL that would have been executed but does NOT execute it.
Advanced callers can use this to include their own additional steps in the same transaction - e.g. recreating views or triggers.
More importantly it gives me a useful hook for writing some unit tests against the generated SQL.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",621989740,table.transform() method for advanced alter table,
https://github.com/simonw/sqlite-utils/issues/114#issuecomment-655786374,https://api.github.com/repos/simonw/sqlite-utils/issues/114,655786374,MDEyOklzc3VlQ29tbWVudDY1NTc4NjM3NA==,9599,simonw,2020-07-08T22:16:54Z,2020-07-08T22:16:54Z,OWNER,"According to https://www.sqlite.org/lang_altertable.html#making_other_kinds_of_table_schema_changes the hardest bits to consider are how to deal with existing foreign key relationships, triggers and views.
I'm OK leaving views as an exercise for the caller - many of these transformations may not need any view changes at all.
Foreign key relationships are important: it should handle these automatically as effectively as possible.
Likewise trigger changes: need to think about what this means.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",621989740,table.transform() method for advanced alter table,
https://github.com/simonw/sqlite-utils/issues/114#issuecomment-655785396,https://api.github.com/repos/simonw/sqlite-utils/issues/114,655785396,MDEyOklzc3VlQ29tbWVudDY1NTc4NTM5Ng==,9599,simonw,2020-07-08T22:14:10Z,2020-07-08T22:14:10Z,OWNER,"Work in progress: not quite right yet, I need smarter logic for how renamed columns are reflected in the generated `INSERT INTO ... SELECT ...` query:
```python
def transform_table(
self,
columns=None,
rename=None,
change_type=None,
pk=None,
foreign_keys=None,
column_order=None,
not_null=None,
defaults=None,
hash_id=None,
extracts=None,
):
assert self.exists(), ""Cannot transform a table that doesn't exist yet""
columns = columns or self.columns_dict
if rename is not None or change_type is not None:
columns = {rename.get(key, key): change_type.get(key, value) for key, value in columns.items()}
new_table_name = ""{}_new_{}"".format(self.name, os.urandom(6).hex())
previous_columns = set(self.columns_dict.keys())
with self.db.conn:
columns = {name: value for (name, value) in columns.items()}
new_table = self.db.create_table(
new_table_name,
columns,
pk=pk,
foreign_keys=foreign_keys,
column_order=column_order,
not_null=not_null,
defaults=defaults,
hash_id=hash_id,
extracts=extracts,
)
# Copy across data - but only for columns that exist in both
new_columns = set(columns.keys())
columns_to_copy = new_columns.intersection(previous_columns)
copy_sql = ""INSERT INTO [{new_table}] ({new_cols}) SELECT {old_cols} FROM [{old_table}]"".format(
new_table=new_table_name,
old_table=self.name,
old_cols="", "".join(""[{}]"".format(col) for col in columns_to_copy),
new_cols="", "".join(""[{}]"".format(rename.get(col, col)) for col in columns_to_copy),
)
self.db.conn.execute(copy_sql)
# Drop the old table
self.db.conn.execute(""DROP TABLE [{}]"".format(self.name))
# Rename the new one
self.db.conn.execute(
""ALTER TABLE [{}] RENAME TO [{}]"".format(new_table_name, self.name)
)
return self
```","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",621989740,table.transform() method for advanced alter table,
https://github.com/simonw/sqlite-utils/issues/114#issuecomment-655783875,https://api.github.com/repos/simonw/sqlite-utils/issues/114,655783875,MDEyOklzc3VlQ29tbWVudDY1NTc4Mzg3NQ==,9599,simonw,2020-07-08T22:09:51Z,2020-07-08T22:10:16Z,OWNER,I can have a convenient `change_type={...}` parameter for changing column types too.,"{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",621989740,table.transform() method for advanced alter table,
https://github.com/simonw/sqlite-utils/issues/114#issuecomment-655782477,https://api.github.com/repos/simonw/sqlite-utils/issues/114,655782477,MDEyOklzc3VlQ29tbWVudDY1NTc4MjQ3Nw==,9599,simonw,2020-07-08T22:06:23Z,2020-07-08T22:06:23Z,OWNER,"Thinking about the method signature:
```python
def transform_table(
self,
columns,
pk=None,
foreign_keys=None,
column_order=None,
not_null=None,
defaults=None,
hash_id=None,
extracts=None,
):
```
This requires the caller to provide the exact set of columns for the new table.
It would be useful if this was optional - if you could omit the columns and have it automatically use the previous columns. This would let you change things like the primary key or the column order using the other arguments.
Even better: allow column renaming using an optional `rename={...}` argument:
```python
db[""dogs""].transform_table(rename={""name"": ""dog_name""})
```","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",621989740,table.transform() method for advanced alter table,
https://github.com/simonw/sqlite-utils/issues/114#issuecomment-655778058,https://api.github.com/repos/simonw/sqlite-utils/issues/114,655778058,MDEyOklzc3VlQ29tbWVudDY1NTc3ODA1OA==,9599,simonw,2020-07-08T21:54:30Z,2020-07-08T21:54:30Z,OWNER,"Don't forget this step:
> If foreign key constraints are enabled, disable them using PRAGMA foreign_keys=OFF. ","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",621989740,table.transform() method for advanced alter table,
https://github.com/simonw/sqlite-utils/issues/114#issuecomment-655677909,https://api.github.com/repos/simonw/sqlite-utils/issues/114,655677909,MDEyOklzc3VlQ29tbWVudDY1NTY3NzkwOQ==,9599,simonw,2020-07-08T18:16:39Z,2020-07-08T18:16:39Z,OWNER,"Since neither the term ""transform"" or ""migrate"" are used in the codebase at the moment, I think I'll go with `.transform_table()` - that leaves the term ""migrate"" available for any future database migrations system (similar to Django's).","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",621989740,table.transform() method for advanced alter table,
https://github.com/simonw/sqlite-utils/issues/114#issuecomment-655677396,https://api.github.com/repos/simonw/sqlite-utils/issues/114,655677396,MDEyOklzc3VlQ29tbWVudDY1NTY3NzM5Ng==,9599,simonw,2020-07-08T18:15:39Z,2020-07-08T18:15:39Z,OWNER,"Alternative possible names:
- `.transform_table()`
- `.migrate()`
- `.transform()`
I'm torn between `.migrate_table()` and `.transform_table()`.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",621989740,table.transform() method for advanced alter table,
https://github.com/simonw/sqlite-utils/issues/114#issuecomment-655677099,https://api.github.com/repos/simonw/sqlite-utils/issues/114,655677099,MDEyOklzc3VlQ29tbWVudDY1NTY3NzA5OQ==,9599,simonw,2020-07-08T18:15:02Z,2020-07-08T18:15:02Z,OWNER,"I'm not so keen on that chained API - it's pretty complicated.
Here's an idea for a much simpler interface. Essentially it lets you say ""take table X and migrate its contents to a new table with this structure - then atomically rename the tables to switch them"":
```python
db[""mytable""].migrate_table({""id"": int, ""name"": str""}, pk=""id"")
```
The `migrate_table()` method would take the same exact signature as the `table.create()` method: https://github.com/simonw/sqlite-utils/blob/a236a6bc771a5a6a9d7e814f1986d461afc422d2/sqlite_utils/db.py#L615-L625","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",621989740,table.transform() method for advanced alter table,
https://github.com/simonw/sqlite-utils/issues/114#issuecomment-655290625,https://api.github.com/repos/simonw/sqlite-utils/issues/114,655290625,MDEyOklzc3VlQ29tbWVudDY1NTI5MDYyNQ==,9599,simonw,2020-07-08T05:15:45Z,2020-07-08T05:15:45Z,OWNER,"Ideally this would all happen in a single transaction, such that other processes talking to the database would not see any inconsistent state while the table copy was taking place. Need to confirm that this is possible. Also refs transactions thoughts in #121.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",621989740,table.transform() method for advanced alter table,
https://github.com/simonw/sqlite-utils/issues/114#issuecomment-636322089,https://api.github.com/repos/simonw/sqlite-utils/issues/114,636322089,MDEyOklzc3VlQ29tbWVudDYzNjMyMjA4OQ==,9599,simonw,2020-05-30T12:08:43Z,2020-05-30T12:08:43Z,OWNER,"Idea: use a chained API to define a complex transition and then execute it all at once. For example:
```python
db[""mytable""].transform().rename(""col1"", ""col_1"") \
.change_type(""col1"", float) \
.execute()
```
","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",621989740,table.transform() method for advanced alter table,