"""Add index to study_id column in trials table

Revision ID: v3.2.0.a
Revises: v3.0.0.d
Create Date: 2023-02-25 13:21:00.730272

"""
from alembic import op


# revision identifiers, used by Alembic.
revision = "v3.2.0.a"
down_revision = "v3.0.0.d"
branch_labels = None
depends_on = None


def upgrade():
    op.create_index(op.f("trials_study_id_key"), "trials", ["study_id"], unique=False)


def downgrade():
    # The following operation doesn't work on MySQL due to a foreign key constraint.
    #
    # mysql> DROP INDEX ix_trials_study_id ON trials;
    # ERROR: Cannot drop index 'ix_trials_study_id': needed in a foreign key constraint.
    op.drop_index(op.f("trials_study_id_key"), table_name="trials")
