update database schema for linking of persons and companies

alembic/versions/03d4f000f445_add_unique_constraint_for_company_.py

@@ -0,0 +1,33 @@
+"""add unique constraint for company person linking table
+
+Revision ID: 03d4f000f445
+Revises: 85577ce9f2ab
+Create Date: 2026-07-22 09:17:46.576581
+
+"""
+
+from typing import Sequence, Union
+
+from alembic import op
+
+# revision identifiers, used by Alembic.
+revision: str = "03d4f000f445"
+down_revision: Union[str, Sequence[str], None] = "85577ce9f2ab"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    """Upgrade schema."""
+    # ### commands auto generated by Alembic - please adjust! ###
+    with op.batch_alter_table("zuordnung_personen_unternehmen") as batch_op:
+        batch_op.create_unique_constraint("uq_un_id_pers_id", ["un_id", "pers_id"])
+    # ### end Alembic commands ###
+
+
+def downgrade() -> None:
+    """Downgrade schema."""
+    # ### commands auto generated by Alembic - please adjust! ###
+    with op.batch_alter_table("zuordnung_personen_unternehmen") as batch_op:
+        batch_op.drop_constraint("uq_un_id_pers_id")
+    # ### end Alembic commands ###