Fix SQLite temp table name must not contain dot

[mvorisek]

Q	A
Type	bug
Fixed issues

Summary

Fix invalid SQL generated when table with schema is given. As it was invalid, this PR is fully BC in sense of the exact generated SQL.

[derrabus]

You know the drill: no test, no merge. 🤗

[mvorisek]

@derrabus how would you like me tested the 1st commit, if the DB name is currently unused?

[derrabus]

You've filed this PR as a bugfix, so that first commit of yours must fix some kind of bug that you can reproduce in a functional test, right?

[mvorisek]

I am splitting this PR into multiple ones. I will update this PR later.

[mvorisek]

This PR is done and has been reworked to contain only a single change with a test.

[greg0ire]

As per the testing guidelines, this change must be covered by an integration test:

Integration (a.k.a. functional) tests are required when the behavior under test is dictated by the logic defined outside of the DBAL. It could be:

• The underlying database platform.
• The underlying database driver.
• SQL syntax and the standard as such.

[mvorisek]

@greg0ire functional test added.

[greg0ire]

Great. Now please improve your commit message. One shouldn't have to read the code to understand what you're talking about.

Build temporary table name from unqualified table name

In some situations, SqlitePlatform::getAlterTableSQL() relies on
a temporary table to store data from the original table while it
gets recreated. The name of this temporary table is built by
concatenating a prefix (__temp__) with the name of the original table.
When the original table name is foo.bar, there is an issue because
then the temporary table name is becomes __temp__foo.bar, and
__temp__foo does not exist. Let us use the unqualified table name
so that the temporary table becomes __temp__bar.

[mvorisek]

Thank you for reviewing this PR. Commit message amended.

[mvorisek]

Two approving reviews, can this PR be merged?

[greg0ire]

I'd love to get a review from Alexander before we do that.

[mvorisek]

Hi @derrabus, can I ask you for your approval too?

[derrabus]

Shouldn't the temporary data table be created in the same schema as the table we want to alter? Right now we cut off the schema and always create the table in the main schema which feels like we're shoveling data between SQLite files for no reason.

[mvorisek]

Shouldn't the temporary data table be created in the same schema as the table we want to alter? Right now we cut off the schema and always create the table in the main schema which feels like we're shoveling data between SQLite files for no reason.

see https://sqlite.org/forum/forumpost/7b70c81a35488424

In https://dbfiddle.uk/CXMRsuHM repro I have confirmed it - CREATE TEMPORARY TABLE always creates temporary table in temp schema, it makes sense, as the temporary table is created in memory and never stored anywhere.

[derrabus]

CREATE TEMPORARY TABLE always creates temporary table in temp schema

TIL, thanks for clarifying. 🙂