html_url,issue_url,id,node_id,user,created_at,updated_at,author_association,body,reactions,issue,performed_via_github_app
https://github.com/simonw/datasette/issues/1671#issuecomment-1074478299,https://api.github.com/repos/simonw/datasette/issues/1671,1074478299,IC_kwDOBm6k_c5ACzzb,9599,2022-03-21T22:20:26Z,2022-03-21T22:20:26Z,OWNER,"Thinking about options for fixing this...
The following query works fine:
```sql
select * from test_view where cast(has_expired as text) = '1'
```
I don't want to start using this for every query, because one of the goals of Datasette is to help people who are learning SQL:
- #1613
If someone clicks on ""View and edit SQL"" from a filtered table page I don't want them to have to wonder why that `cast` is there.
But... for querying views, the `cast` turns out to be necessary.
So one fix would be to get the SQL generating logic to use casts like this any time it is operating against a view.
An even better fix would be to detect which columns in a view come from a table and which ones might not, and only use casts for the columns that aren't definitely from a table.
The trick I was exploring here might be able to help with that:
- #1293 ","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1174655187,
https://github.com/simonw/datasette/issues/1671#issuecomment-1074470568,https://api.github.com/repos/simonw/datasette/issues/1671,1074470568,IC_kwDOBm6k_c5ACx6o,9599,2022-03-21T22:11:14Z,2022-03-21T22:12:49Z,OWNER,"I wonder if this will be a problem with generated columns, or with SQLite strict tables?
My hunch is that strict tables will continue to work without any changes, because https://www.sqlite.org/stricttables.html says nothing about their impact on comparison operations. I should test this to make absolutely sure though.
Generated columns have a type, so my hunch is they will continue to work fine too.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1174655187,
https://github.com/simonw/datasette/issues/1671#issuecomment-1074468450,https://api.github.com/repos/simonw/datasette/issues/1671,1074468450,IC_kwDOBm6k_c5ACxZi,9599,2022-03-21T22:08:35Z,2022-03-21T22:10:00Z,OWNER,"Relevant section of the SQLite documentation: [3.2. Affinity Of Expressions](https://www.sqlite.org/datatype3.html#affinity_of_expressions):
> When an expression is a simple reference to a column of a real table (not a [VIEW](https://www.sqlite.org/lang_createview.html) or subquery) then the expression has the same affinity as the table column.
In your example, `has_expired` is no longer a simple reference to a column of a real table, hence the bug.
Then [4.2. Type Conversions Prior To Comparison](https://www.sqlite.org/datatype3.html#type_conversions_prior_to_comparison) fills in the rest:
> SQLite may attempt to convert values between the storage classes INTEGER, REAL, and/or TEXT before performing a comparison. Whether or not any conversions are attempted before the comparison takes place depends on the type affinity of the operands. ","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1174655187,
https://github.com/simonw/datasette/issues/1671#issuecomment-1074465536,https://api.github.com/repos/simonw/datasette/issues/1671,1074465536,IC_kwDOBm6k_c5ACwsA,9599,2022-03-21T22:04:31Z,2022-03-21T22:04:31Z,OWNER,"Oh this is fascinating! I replicated the bug (thanks for the steps to reproduce) and it looks like this is down to the following:
Against views, `where has_expired = 1` returns different results from `where has_expired = '1'`
This doesn't happen against tables because of SQLite's [type affinity](https://www.sqlite.org/datatype3.html#type_affinity) mechanism, which handles the type conversion automatically.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1174655187,