按日期存储在字符串中的房间订单

Question

    @Query("SELECT * FROM product_data_table ORDER BY strftime('%Y-%d-%m-%Y', product_end_date)")
        fun getAllProductsOrderByEndDate(): LiveData<List<Product>>

@Entity(tableName = "product_data_table")
data class Product(

 @ColumnInfo(name = "product_end_date")
    var end_date: String,
)

Answer 1

我这样实现了按日期排序：

道：

//depends on your needs you can delete "DESC", it reverses ordering
@Query("SELECT * FROM Folders ORDER BY date DESC")
fun getFoldersLV(): LiveData<List<Folders>>

将日期添加到数据库：

//DateTime - my own converter class
// and you can format date as you wish(for example "yyyy/MM/dd")
// but don't use reversed ordering of date, because you won't be able to order it
val currentDate: String = DateTime.dateToString(DateTime.getCurrentDateTime(), "yyyy/MM/dd HH:mm:ss")

fun getCurrentDateTime(): Date {
    return Calendar.getInstance().time
}

fun dateToString(date: Date, format: String, locale: Locale = Locale.getDefault()): String {
    val formatter = SimpleDateFormat(format, locale)
    return formatter.format(date)
}

//I need this class to get date as Date type again for some actions, but I think you don't need it
fun stringToDate(dateString: String?, format: String = "dd/MM/yyyy HH:mm", locale: Locale = Locale.getDefault()): Date {
    val formatter = SimpleDateFormat(format, locale)
    return formatter.parse(dateString)
}