# this move is about adding a slice x users many to many relation ship for modelling
# regular "membership" of users in a slice

from sqlalchemy import Table, MetaData, Column, ForeignKey
from sqlalchemy import Integer, String

metadata = MetaData()

# this is needed by migrate so it can locate 'records.record_id'
records = \
    Table('records', metadata,
          Column('record_id', Integer, primary_key=True),
          )

# slice x user (researchers) association
slice_researcher_table = \
    Table('slice_researcher', metadata,
          Column('slice_id', Integer, ForeignKey(
              'records.record_id'), primary_key=True),
          Column('researcher_id', Integer, ForeignKey(
              'records.record_id'), primary_key=True),
          )


def upgrade(migrate_engine):
    metadata.bind = migrate_engine
    slice_researcher_table.create()


def downgrade(migrate_engine):
    metadata.bind = migrate_engine
    slice_researcher_table.drop()