def test__add_field_if_not_exists(self):
"""
Should add a field only if it does not already exist.
"""
db = RockfishDatabaseConnection(':memory:')
field_name = 'field1'
fields = [(field_name, 'REAL', None, False, False)]
db._create_table_if_not_exists('table1', fields)
# should have the field
current_fields = db._get_fields('table1')
self.assertEqual(len(current_fields), 1)
# try to add the field again
db._add_field_if_not_exists('table1', field_name)
