All foreign keys added and removed despite no changes

[OD1995]

Describe the bug
No changes made to the table but commands are autogenerated to drop and then create foreign keys

Expected behavior
No changes made to the table so the commands to drop and then create foreign keys shouldn't have been autogenerated

To Reproduce
Competitions.py

from uuid import UUID
from sqlalchemy import ForeignKey, String
from app import db
from sqlalchemy.orm import Mapped, mapped_column

class Competition(db.Model):
    __tablename__ = 'competitions'

    competition_id: Mapped[UUID] = mapped_column(primary_key=True)
    data_source_competition_id: Mapped[str] = mapped_column(String(100))
    competition_name: Mapped[str] = mapped_column(String(100))
    team_season_id: Mapped[UUID] = mapped_column(
        ForeignKey("team_seasons.team_season_id", name="fk_team_seasons_team_season_id"),
        index=True
    )

autogenerated migration

from alembic import op
import sqlalchemy as sa


# revision identifiers, used by Alembic.
revision = 'f1e78ca81ee6'
down_revision = '6fdb82a4eb62'
branch_labels = None
depends_on = None


def upgrade():
    # ### commands auto generated by Alembic - please adjust! ###
    with op.batch_alter_table('competitions', schema=None) as batch_op:
        batch_op.drop_constraint('fk_team_seasons_team_season_id', type_='foreignkey')
        batch_op.create_foreign_key('fk_team_seasons_team_season_id', 'team_seasons', ['team_season_id'], ['team_season_id'])

Versions.

• OS: Windows 11
• Python: 3.11.0
• Alembic: 1.13.3
• SQLAlchemy: 2.0.35
• Database: MySQL
• DBAPI: ?

[zzzeek]

Hi -

what version of MySQL and how is it configured? if an older version of MySQL you might be defaulting to the MyISAM engine which will not have the FK definitions. or there might be some casing convention in play that is confusing the comparison of keys.

need to know exact MySQL version

[OD1995]

Could it maybe be something to do with the MySQL 5.7.28-TiDB-v7.1.3-serverless version?

[zzzeek]

it's certainly a big possibility, so....what is that?

[zzzeek]

i mean there is a "fix" for this but it's tricky if we can't test it

[OD1995]

My database is with TiDB Cloud Serverless: https://www.pingcap.com/tidb-cloud-serverless/

Honestly, you've gone way beyond the help I hoped for when I made the post originally. I really appreciate your help but I'm very happy to end this here

[zzzeek]

OK sure. so this is a mysql-"like" database. We could fix this but might be tricky to test. we'll keep it in mind thanks for the debug info!