Added initial_weight and empty_weight to spool

migrations/versions/2024_03_26_1349-304a32906234_spool_weight_population.py

@@ -0,0 +1,46 @@
+"""spool weight population.
+
+Revision ID: 304a32906234
+Revises: aafcd7fb0e84
+Create Date: 2024-03-26 13:49:26.594399
+"""
+import sqlalchemy as sa
+from alembic import op
+
+# revision identifiers, used by Alembic.
+revision = '304a32906234'
+down_revision = 'aafcd7fb0e84'
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    filament = sa.Table('filament',
+        sa.MetaData(),
+        sa.Column('id', sa.Integer, primary_key=True),
+        sa.Column('weight', sa.Float(), nullable=True),
+        sa.Column('spool_weight', sa.Float(), nullable=True))
+    
+    spool = sa.Table(
+        'spool',
+        sa.MetaData(),
+        sa.Column('id', sa.Integer, primary_key=True),
+        sa.Column('filament_id', sa.Integer),
+        sa.Column('initial_weight', sa.Float(), nullable=False, comment="The initial total weight of the spool (gross weight)."),
+        sa.Column('empty_weight', sa.Float(), nullable=False, comment="The weight of the empty spool (tare weight).")
+    ) 
+    
+    initial_weight = sa.select((filament.c.weight + filament.c.spool_weight).label("initial_weight")).where(filament.c.id == spool.c.filament_id).scalar_subquery()
+    empty_weight = sa.select(filament.c.spool_weight).where(filament.c.id == spool.c.filament_id).scalar_subquery()
+
+    set_initial_weight = sa.update(spool).values(initial_weight=initial_weight)
+    op.execute(set_initial_weight)
+
+    set_empty_weight = sa.update(spool).values(empty_weight=empty_weight)
+    op.execute(set_empty_weight)
+    pass
+
+
+def downgrade() -> None:
+    """Perform the downgrade."""
+    pass