return "CONSTRAINT ? UNIQUE (?)", []interface{}{clause.Column{Name: uni.Name}, clause.Column{Name: uni.Field.DBName}}
}

// ParseUniqueConstraints parse schema unique constraints
func (schema *Schema) ParseUniqueConstraints() map[string]UniqueConstraint {
	uniques := make(map[string]UniqueConstraint)
	for _, field := range schema.Fields {
		if field.Unique {