sql += " ON DELETE " + constraint.OnDelete
	}

	if constraint.OnUpdate != "" {
		sql += " ON UPDATE " + constraint.OnUpdate
	}

	foreignKeys := make([]interface{}, 0, len(constraint.ForeignKeys))
	for _, field := range constraint.ForeignKeys {
		foreignKeys = append(foreignKeys, clause.Column{Name: field.DBName})
	}

	references := make([]interface{}, 0, len(constraint.References))

}

// ToQueryValues to query values
func ToQueryValues(table string, foreignKeys []string, foreignValues [][]interface{}) (interface{}, []interface{}) {
	queryValues := make([]interface{}, len(foreignValues))
	if len(foreignKeys) == 1 {
		for idx, r := range foreignValues {
			queryValues[idx] = r[0]
		}

		return clause.Column{Table: table, Name: foreignKeys[0]}, queryValues
	}