remove schema of placeholder

ereuse_devicehub/migrations/versions/aeca9fb50cc6_add_placeholder.py

@@ -48,9 +48,10 @@ def upgrade():
         sa.Column('device_id', sa.BigInteger(), nullable=False),
         sa.ForeignKeyConstraint(['device_id'], [f'{get_inv()}.device.id']),
         sa.PrimaryKeyConstraint('id'),
-        schema=f'{get_inv()}',
     )
+    op.execute("CREATE SEQUENCE placeholder_seq START 1;")
 
 
 def downgrade():
-    op.drop_table('placeholder', schema=f'{get_inv()}')
+    op.drop_table('placeholder')
+    op.execute("DROP SEQUENCE placeholder_seq;")

ereuse_devicehub/resources/device/models.py

@@ -827,6 +827,7 @@ class DisplayMixin:
 
 
 class Placeholder(Thing):
+    __table_args__ = {'schema': ''}
     id = Column(BigInteger, Sequence('placeholder_seq'), primary_key=True)
     pallet = Column(Unicode(), nullable=True)
     phid = Column(Unicode(), nullable=False, default=create_phid)