21def upgrade():
   22    yesno_values = ENUM(*YESNO_VALUES, name=YESNO_NAME, create_type=False)
   23 
   24    if op.get_context().bind.dialect.name != 'mssql':
   25        op.alter_column('ps_endpoints', 'suppress_q850_reason_header', type_=yesno_values,
   26                        new_column_name='suppress_q850_reason_headers')
   27    else:
   28        op.alter_column('ps_endpoints', 'suppress_q850_reason_header', existing_type=yesno_values, type_=sa.String(3),
   29                        new_column_name='suppress_q850_reason_headers')
   30        yesno_values = ENUM(*YESNO_VALUES, name=YESNO_NAME, create_type=True)
   31        op.alter_column('ps_endpoints', 'suppress_q850_reason_headers', existing_type=sa.String(3), type_=yesno_values)
   32 
   33