// PrimaryKey returns the index is primary key or not.
func (idx Index) PrimaryKey() (isPrimaryKey bool, ok bool) {
	return idx.PrimaryKeyValue.Bool, idx.PrimaryKeyValue.Valid
}

// Unique returns whether the index is unique or not.
func (idx Index) Unique() (unique bool, ok bool) {
	return idx.UniqueValue.Bool, idx.UniqueValue.Valid
}

// Option return the optional attribute of the index
func (idx Index) Option() string {

							return
						}
						subName = composite
					}
					name = field.Schema.namer.IndexName(
						field.Schema.Table, subName)
				}

				if (k == "UNIQUEINDEX") || settings["UNIQUE"] != "" {
					settings["CLASS"] = "UNIQUE"
				}

				priority, err := strconv.Atoi(settings["PRIORITY"])
				if err != nil {
					priority = 10
				}

				indexes = append(indexes, Index{
					Name:    name,