Add migration for new session tables

Author: PeterJCLaw

migrations/versions/27f63e48c6c4_create_sessions.py

@@ -0,0 +1,49 @@
+"""Create Sessions
+
+Revision ID: 27f63e48c6c4
+Revises: d4e3b890e3d7
+Create Date: 2021-01-09 11:57:18.916146
+
+"""
+import sqlalchemy as sa
+from alembic import op
+
+# revision identifiers, used by Alembic.
+revision = '27f63e48c6c4'
+down_revision = 'd4e3b890e3d7'
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.create_table(
+        'session',
+        sa.Column('id', sa.Integer(), nullable=False),
+        sa.Column('name', sa.String(), nullable=False),
+        sa.Column('username', sa.String(), nullable=False),
+        sa.Column(
+            'created',
+            sa.DateTime(timezone=True),
+            server_default=sa.text('(CURRENT_TIMESTAMP)'),
+            nullable=False,
+        ),
+        sa.PrimaryKeyConstraint('id'),
+        sa.UniqueConstraint('name'),
+    )
+    op.create_table(
+        'choice_for_session',
+        sa.Column('choice_id', sa.Integer(), nullable=False),
+        sa.Column('session_id', sa.Integer(), nullable=False),
+        sa.ForeignKeyConstraint(['choice_id'], ['choice_history.id']),
+        sa.ForeignKeyConstraint(['session_id'], ['session.id']),
+        sa.PrimaryKeyConstraint('choice_id', 'session_id'),
+    )
+    # ### end Alembic commands ###
+
+
+def downgrade() -> None:
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_table('choice_for_session')
+    op.drop_table('session')
+    # ### end Alembic commands ###