DB migration: remove shifts uniqueness constraint

We really care about dates, not hours, so dupes not a big deal.

Author: c-simpson

src/server/alembic/versions/d80cb6df0fa2_rmv_shifts_uniqueness_constraint.py

@@ -0,0 +1,32 @@
+"""rmv shifts uniqueness constraint
+
+Revision ID: d80cb6df0fa2
+Revises: 90f471ac445c
+Create Date: 2023-03-18 16:22:23.282568
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = 'd80cb6df0fa2'
+down_revision = '90f471ac445c'
+branch_labels = None
+depends_on = None
+
+# It's probably more likely that a duplicate row is actually a real shift with a bad (dupe)
+# like Saturday, Saturday instead of Saturday, Sunday 
+# We really care about last shift so this is not critical
+
+def upgrade():
+    op.drop_constraint( "uq_shift", "volgisticsshifts") 
+
+def downgrade():
+    # op.create_unique_constraint( "uq_shift", "volgisticsshifts",  ["volg_id", "assignment", "from_date", "hours"] ) 
+    # This will fail if you have any dupes
+    # running 
+    #    ALTER TABLE "public"."volgisticsshifts" ADD CONSTRAINT "uq_shift" UNIQUE( "volg_id", "assignment", "from_date", "hours" );
+    # will fail and tell you of any dupes so you can fix
+
+    pass