fix(db): guards against error if constraint already dropped (#5850)

Author: whitdog47

src/dispatch/database/revisions/tenant/versions/2025-03-11_37406cca756c.py

@@ -5,25 +5,45 @@
 Create Date: 2025-03-11 16:26:52.406726
 
 """
-from alembic import op
 
+from alembic import op
+from sqlalchemy.engine.reflection import Inspector
 
 # revision identifiers, used by Alembic.
-revision = '37406cca756c'
-down_revision = 'da444de005a6'
+revision = "37406cca756c"
+down_revision = "da444de005a6"
 branch_labels = None
 depends_on = None
 
 
 def upgrade():
-    # ### commands auto generated by Alembic - please adjust! ###
-    op.drop_constraint('case_cost_case_cost_type_id_fkey', 'case_cost', type_='foreignkey')
-    op.create_foreign_key(None, 'case_cost', 'case_cost_type', ['case_cost_type_id'], ['id'], ondelete='CASCADE')
+    # Get the connection and inspector
+    conn = op.get_bind()
+    inspector = Inspector.from_engine(conn)
+
+    # Check if the constraint exists
+    constraints = inspector.get_foreign_keys("case_cost")
+    constraint_names = [constraint["name"] for constraint in constraints]
+
+    # Drop the constraint if it exists
+    if "case_cost_case_cost_type_id_fkey" in constraint_names:
+        op.drop_constraint("case_cost_case_cost_type_id_fkey", "case_cost", type_="foreignkey")
+
+    # Create the new foreign key constraint
+    op.create_foreign_key(
+        None, "case_cost", "case_cost_type", ["case_cost_type_id"], ["id"], ondelete="CASCADE"
+    )
     # ### end Alembic commands ###
 
 
 def downgrade():
     # ### commands auto generated by Alembic - please adjust! ###
-    op.drop_constraint(None, 'case_cost', type_='foreignkey')
-    op.create_foreign_key('case_cost_case_cost_type_id_fkey', 'case_cost', 'case_cost_type', ['case_cost_type_id'], ['id'])
+    op.drop_constraint(None, "case_cost", type_="foreignkey")
+    op.create_foreign_key(
+        "case_cost_case_cost_type_id_fkey",
+        "case_cost",
+        "case_cost_type",
+        ["case_cost_type_id"],
+        ["id"],
+    )
     # ### end Alembic commands ###