* More SQL tests
* Remove duplicate
* Fix another test
* Temp fix
* More temporay fixes
* More green
* Another green
* Another one
* Fix counts
* Temporary change
* Fix tests
* Auto-commit work in progress before clean build on 2024-09-06 10:53:46
* Another fix
* Green
* Specialise ensure_query_has_no_holes
* cleanup
* Cleanup
* Cleanup
* Clean
* Code review changes
- Linting updates.
- Add an `Examples.welcome` and adjust the start up project to use it.
- Merge all of Cass's work into the source code.
- Make example render in mono space font.
This implements `DB_Column.with`, which uses `WITH ... AS` SQL clauses to remove duplicates in the generated SQL.
After a discussion with @radeusgd, we concluded that we will probably want a more complete CTE implementation, so this one is useful for now to deal with big queries (like `round`).
# Important Notes
Still to do in this PR:
- [x] Rename `with` to `let` (or something similar)
- [x] tests
- [x] documentation
- [x] remove `State` hack by moving query generation into a class and using a `Ref` field for scoping
Results on `round_float`:
| --- | SQL length in characters (unprettified) | SQL length in lines (prettified) |
| --- | --- | --- |
| Without CTEs | 13193 | 851 |
| With CTEs | 3644 | 187 |
Compare the SQL:
[without-ctes.sql.txt](https://github.com/user-attachments/files/16629356/without-ctes.sql.txt)
[with-ctes.sql.txt](https://github.com/user-attachments/files/16629357/with-ctes.sql.txt)
Update, with name shortening:
| --- | SQL length in characters (unprettified) | SQL length in lines (prettified) |
| --- | --- | --- |
| Without CTEs | 13193 | 853 |
| With CTEs | 2427 | 176 |
[without-cte.txt](https://github.com/user-attachments/files/16694328/without-cte.txt)
[with-cte.txt](https://github.com/user-attachments/files/16694327/with-cte.txt)
- Enables the `..` autoscoping style for creating Atoms in expressions.
- Add type checking to methods in columns.
- Auto wrap returns from method in expressions into a column as needed.
- Remove `Time_Period.Day` to remove confusion..
- Closes#10716 by un-marking the `Snowflake_Connection` as `private`.
- Does the same to `SQLServer_Connection`.
- Makes sure that `Snowflake_Connection` has correct visualization and enables links for it.
- Adds a fallback in `to_default_visualization_data` and in Table's `prepare_visualization` so that if `to_js_object` of a given type is malformed, we still get some kind of visualization + debug info about the underlying error.
Fixes#10609 by rewriting all our upload-related operations to rely on `DDL_Transaction` - an abstraction that handles 'transactionality' of `CREATE TABLE` statements dependent on if a given backend allows DDLs within transactions or not (if not it emulates transactionality by creating the tables outside of transaction and then dropping them on rollback).
