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))

			rel           = association.Relationship
			primaryFields []*schema.Field
			foreignKeys   []string
			updateAttrs   = map[string]interface{}{}
			conds         []clause.Expression
		)

		for _, ref := range rel.References {
			if ref.PrimaryValue == "" {
				primaryFields = append(primaryFields, ref.PrimaryKey)
				foreignKeys = append(foreignKeys, ref.ForeignKey.DBName)
				updateAttrs[ref.ForeignKey.DBName] = nil
			} else {