Implement Connection.GetSchema

[hazzik]

This PR implements Connection.GetSchema.

Standard collections: ✔️ MetaDataCollections ✔️ Restrictions ✔️ ReservedWords ❌ DataSourceInformation ❌ DataTypes

Non standard common collections ✔️ Tables ✔️ Columns ✔️ ForeignKeys ✔️ Indexes

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 88.41%. Comparing base (6270bac) to head (1033016). Report is 35 commits behind head on develop.

:exclamation: Your organization needs to install the Codecov GitHub app to enable full functionality.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## develop #185 +/- ## =========================================== + Coverage 87.83% 88.41% +0.58% =========================================== Files 42 54 +12 Lines 1504 1761 +257 Branches 217 239 +22 =========================================== + Hits 1321 1557 +236 - Misses 127 146 +19 - Partials 56 58 +2 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.

[coveralls]

Pull Request Test Coverage Report for Build 9155702909

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

• For more information on this, see Tracking coverage changes with pull request builds.
• To avoid this issue with future PRs, see these Recommended CI Configurations.
• For a quick fix, rebase this PR at GitHub. Your next report should be accurate.

Details

• 121 of 121 (100.0%) changed or added relevant lines in 2 files are covered.
• 8 unchanged lines in 4 files lost coverage.
• Overall coverage increased (+0.7%) to 90.216%

---

Files with Coverage Reduction	New Missed Lines	%
DuckDB.NET.Data/DuckDBCommand.cs	1	89.83%
DuckDB.NET.Data/Internal/Reader/VectorDataReaderBase.cs	1	88.27%
DuckDB.NET.Data/Internal/PreparedStatement.cs	3	93.33%
DuckDB.NET.Data/Internal/Reader/DateTimeVectorDataReader.cs	3	90.2%
<!--	Total:	8		-->

Totals
Change from base Build 9119577775:	0.7%
Covered Lines:	1615
Relevant Lines:	1761

---

💛 - Coveralls

[Giorgi]

Is it still WIP?

[hazzik]

Yes, want to implement a few more essential collections.

[Giorgi]

I'll mark it as Draft. Please mark it ready for review when it's finished. Thanks

[hazzik]

Ok. This is ready for review now. I've implemented almost all metadata I wanted, except IndexColumns, that seems to be impossible to implement. Also, I have not implemented DataTypes and DataSourceInformation standard collections as I don't have interest in them. If that's is required it would be possible to implement later.

[Giorgi]

Thanks, I'll try to review it in the next few days. Is there any documentation on how GetSchema should work and what kind of structure it should return?

[hazzik]

The documentation is really loose, the basic description of how it should work is here: https://learn.microsoft.com/en-us/dotnet/framework/data/adonet/retrieving-database-schema-information.

With common schema collections and custom collections that are available via informational_schema catalog it is more-or-less settled, but for custom collections it becomes trickier (in context of this PR it is only Indexes collection): the column names and information do not often match between providers.

[Giorgi]

Thanks, merged.

[hazzik]

Thank you

[Giorgi]

@hazzik This is now live on NuGet.