Atlas driver support for YDB

[kprokopenko]

Hello there! @LostImagin4tion is currently working on adding support for YDB to ent. Atlas migration support for YDB is a prerequisite for completing the ent integration, as ent relies on Atlas for its schema migration engine.

This PR introduces Atlas driver support for YDB, including schema inspection, diffing, and migration planning/applying. The implementation follows the same patterns used by existing drivers (postgres, mysql, sqlite).

What's included

Core driver (sql/ydb/):

File	Description
driver.go	Atlas' driver implementation for YDB
types.go	YDB type constants and custom schema types
inspect.go	Schema inspection via native YDB Scheme and Table APIs. Inspects columns, primary keys, and secondary indexes
diff.go	Schema diffing via sqlx.Diff with a YDB-specific DiffDriver. Handles table, column, and index changes. No foreign key support (YDB limitation)
migrate.go	Migration planning and applying. Supports CREATE TABLE, DROP TABLE, RENAME TABLE, ADD/DROP COLUMN, ADD/DROP/RENAME INDEX. All plans are non-transactional
convert.go	Bidirectional type conversion covering all YDB types
attributes.go	IndexAttributes for YDB-specific index properties

YDB-specific design decisions

• Database path as schema - YDB's database path (e.g. /local/dir1/table1) maps to Atlas's schema concept. Tables can live in subdirectories
• ydb.Unwrap - using Unwrap() method to extract the native YDB driver from *sql.DB, which gives access to native Scheme and Table APIs for database inspection
• Non-transactional DDL: YDB DDL is not transactional, so all migration plans set Transactional: false
• No foreign keys: YDB does not support foreign keys; the differ explicitly skips FK-related logic

New Dependencies

• github.com/ydb-platform/ydb-go-sdk/v3 v3.125.4
• github.com/ydb-platform/ydb-go-genproto (indirect, for YDB protobuf types)

[a8m]

Thanks for the contribution, @kprokopenko. Unfortunately, we don't accept external contribution at this stage to Atlas drivers, as I wrote in the past here: #3057 (comment)

If the YDB team is interested in having this database supported in Atlas, we would be more than happy to partner with them. However, development and maintenance for these databases happen in a separate repository. If this is relevant, feel free to drop me a message on our Discord and we can take it from there. Cheers!

[LostImagin4tion]

If the YDB team is interested in having this database supported in Atlas, we would be more than happy to partner with them. However, development and maintenance for these databases happen in a separate repository. If this is relevant, feel free to drop me a message on our Discord and we can take it from there. Cheers!

Hello! Thank you for replying so quickly.
Do you plan to implement some kind of plugin system? In order to make adding new driver would be not so invasive