sql - 在 SQL 中将 DateTime 转换为 "n Hours Ago"的最佳方法

Question

我编写了一个 SQL 函数，将 SQL 中的日期时间值转换为更友好的“n 小时前”或“n 天前”等类型的消息。我想知道是否有更好的方法来做到这一点。

(是的，我知道“不要在 SQL 中这样做”，但出于设计原因，我必须这样做)。

这是我写的函数:

CREATE FUNCTION dbo.GetFriendlyDateTimeValue
(
    @CompareDate DateTime
)
RETURNS nvarchar(48)
AS
BEGIN
    DECLARE @Now DateTime
    DECLARE @Hours int
        DECLARE @Suff nvarchar(256)
    DECLARE @Found bit

    SET @Found = 0
    SET @Now = getDate()
    SET @Hours = DATEDIFF(MI, @CompareDate, @Now)/60

    IF @Hours <= 1
    BEGIN
        SET @Suff = 'Just Now'
        SET @Found = 1
        RETURN @Suff
    END

    IF @Hours < 24
    BEGIN
        SET @Suff = ' Hours Ago'
        SET @Found = 1
    END

    IF @Hours >= 8760 AND @Found = 0
    BEGIN
        SET @Hours = @Hours / 8760
        SET @Suff = ' Years Ago'
        SET @Found = 1
    END

    IF @Hours >= 720 AND @Found = 0
    BEGIN
        SET @Hours = @Hours / 720
        SET @Suff = ' Months Ago'
        SET @Found = 1
    END

    IF @Hours >= 168 AND @Found = 0
    BEGIN
        SET @Hours = @Hours / 168
        SET @Suff = ' Weeks Ago'
        SET @Found = 1
    END

    IF @Hours >= 24 AND @Found = 0
    BEGIN
        SET @Hours = @Hours / 24
        SET @Suff = ' Days Ago'
        SET @Found = 1
    END

    RETURN Convert(nvarchar, @Hours) + @Suff
END

Answer 1

正如你所说，我可能不会用 SQL 来做，但作为一个思考练习，有一个 MySQL 实现:

CASE
    WHEN compare_date between date_sub(now(), INTERVAL 60 minute) and now() 
        THEN concat(minute(TIMEDIFF(now(), compare_date)), ' minutes ago')

    WHEN datediff(now(), compare_date) = 1 
        THEN 'Yesterday'

    WHEN compare_date between date_sub(now(), INTERVAL 24 hour) and now() 
        THEN concat(hour(TIMEDIFF(NOW(), compare_date)), ' hours ago')

    ELSE concat(datediff(now(), compare_date),' days ago')
END

基于在 MySQL Date and Time 上看到的类似样本手册页