diff --git a/ereuse_devicehub/migrations/versions/aeca9fb50cc6_add_placeholder.py b/ereuse_devicehub/migrations/versions/aeca9fb50cc6_add_placeholder.py
new file mode 100644
index 00000000..0eef82bd
--- /dev/null
+++ b/ereuse_devicehub/migrations/versions/aeca9fb50cc6_add_placeholder.py
@@ -0,0 +1,60 @@
+"""add placeholder
+
+Revision ID: aeca9fb50cc6
+Revises: 8d4fe4b497b3
+Create Date: 2022-06-27 13:09:30.497678
+
+"""
+import citext
+import sqlalchemy as sa
+from alembic import context, op
+
+# revision identifiers, used by Alembic.
+revision = 'aeca9fb50cc6'
+down_revision = '8d4fe4b497b3'
+branch_labels = None
+depends_on = None
+
+
+def get_inv():
+    INV = context.get_x_argument(as_dictionary=True).get('inventory')
+    if not INV:
+        raise ValueError("Inventory value is not specified")
+    return INV
+
+
+def upgrade():
+    # creating placeholder table
+    # con = op.get_bind()
+    # sql = f"CREATE SEQUENCE {get_inv()}.placeholder_id_seq START 1;"
+    # con.execute(sql)
+
+    op.create_table(
+        'placeholder',
+        sa.Column(
+            'updated',
+            sa.TIMESTAMP(timezone=True),
+            server_default=sa.text('CURRENT_TIMESTAMP'),
+            nullable=False,
+        ),
+        sa.Column(
+            'created',
+            sa.TIMESTAMP(timezone=True),
+            server_default=sa.text('CURRENT_TIMESTAMP'),
+            nullable=False,
+        ),
+        sa.Column('id', sa.BigInteger(), nullable=False),
+        sa.Column('id_device_supplier', sa.Unicode(), nullable=True),
+        sa.Column('pallet', sa.Unicode(), nullable=True),
+        sa.Column('info', citext.CIText(), nullable=True),
+        sa.Column('device_id', sa.BigInteger(), nullable=False),
+        sa.Column('binding_id', sa.BigInteger(), nullable=True),
+        sa.ForeignKeyConstraint(['device_id'], [f'{get_inv()}.device.id']),
+        sa.ForeignKeyConstraint(['binding_id'], [f'{get_inv()}.device.id']),
+        sa.PrimaryKeyConstraint('id'),
+        schema=f'{get_inv()}',
+    )
+
+
+def downgrade():
+    op.drop_table('placeholder', schema=f'{get_inv()}')
diff --git a/ereuse_devicehub/resources/device/models.py b/ereuse_devicehub/resources/device/models.py
index 003e0f3d..30c16c5b 100644
--- a/ereuse_devicehub/resources/device/models.py
+++ b/ereuse_devicehub/resources/device/models.py
@@ -793,8 +793,7 @@ class DisplayMixin:
 
 class Placeholder(Thing):
     id = Column(BigInteger, Sequence('placeholder_seq'), primary_key=True)
-    phid = Column(Unicode(), check_lower('phid'), unique=False)
-    pallet = Column(BigInteger, nullable=True)
+    pallet = Column(Unicode(), nullable=True)
     pallet.comment = "used for identification where from where is this placeholders"
     info = db.Column(CIText())
     info.comment = "more info of placeholders"
@@ -803,29 +802,29 @@ class Placeholder(Thing):
         "Identification used for one supplier of one placeholders"
     )
 
-    placeholder_id = db.Column(
+    device_id = db.Column(
         BigInteger,
         db.ForeignKey(Device.id),
         nullable=False,
     )
-    placeholder = db.relationship(
+    device = db.relationship(
         Device,
-        backref=backref('placeholder', lazy=True),
-        primaryjoin=placeholder_id == Device.id,
+        backref=backref('placeholder', lazy=True, uselist=False),
+        primaryjoin=device_id == Device.id,
     )
-    placeholder_id.comment = "datas of the placeholder"
+    device_id.comment = "datas of the placeholder"
 
-    device_id = db.Column(
+    binding_id = db.Column(
         BigInteger,
         db.ForeignKey(Device.id),
         nullable=True,
     )
-    device = db.relationship(
+    binding = db.relationship(
         Device,
-        backref=backref('binding', lazy=True),
-        primaryjoin=placeholder_id == Device.id,
+        backref=backref('binding', lazy=True, uselist=False),
+        primaryjoin=binding_id == Device.id,
     )
-    device_id.comment = "device with snapshots than is linked to the placeholder"
+    binding_id.comment = "device with snapshots than is linked to the placeholder"
 
 
 class Computer(Device):