Breaking data change

.vscode/settings.json

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+{
+  "workbench.colorTheme": "Activate UMBRA protocol"
+}

contracts/order_details.yaml

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+id: 7b7eabe6-a52a-4e19-8bf3-9015eadbbed0
+dataAssetResourceName: postgres://prod.store.com:5432:tutorial.public.order_details
+spec-version: 0.1.0
+name: OrderDetails
+namespace: Tutorial
+doc: Details of items for an order. Each row represents the different items that were part of an order including their quantity and price.
+owner: chadgable@gable.ai
+schema:
+  - name: order_id
+    doc: The identifier of the order the item is associated with
+    type: int32
+  - name: product_id
+    doc: The identifier of the product that was ordered
+    type: int32
+  - name: quantity
+    doc: The quantity of the product in the order
+    type: int32
+  - name: total_price
+    doc: The total price of the item in the order
+    type: decimal256
+  - name: vendor_id
+    doc: The identifier of the vendor that the product was ordered from
+    type: int32

db_migrations/7a341d712aa5_order_detail_changes.py

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+"""order_detail changes
+
+Revision ID: 7a341d712aa5
+Revises: 78da3a78bfd6
+Create Date: 2023-09-29 13:22:35.204135
+
+"""
+
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision: str = "7a341d712aa5"
+down_revision: Union[str, None] = "78da3a78bfd6"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    # Make the vendor optional
+    op.alter_column(
+        "order_details",
+        "vendor_id",
+        nullable=True,
+    )
+
+    # Convert existing values to integers (for example, if representing cents)
+    op.execute("UPDATE order_details SET unit_price = ROUND(unit_price * 100)")
+    op.execute("UPDATE order_details SET total_price = ROUND(total_price * 100)")
+
+    # Alter the column type
+    op.alter_column("order_details", "unit_price", type_=sa.Integer)
+    op.alter_column("order_details", "total_price", type_=sa.Integer)
+
+
+def downgrade() -> None:
+    op.alter_column(
+        "order_details",
+        "vendor_id",
+        nullable=False,
+    )
+
+    # Alter the column type back to Numeric
+    op.alter_column("order_details", "unit_price", type_=sa.Numeric(10, 2))
+    op.alter_column("order_details", "total_price", type_=sa.Numeric(10, 2))
+
+    # Convert integer values back to their decimal representations
+    op.execute("UPDATE order_details SET unit_price = total_price / 100.0")
+    op.execute("UPDATE order_details SET total_price = total_price / 100.0")