在 Go 中进行日期比较有什么选择吗？我必须根据日期和时间对数据进行排序 - 独立。所以我可能允许一个对象出现在一个日期范围内，只要它也出现在一个时间范围内。在这个模型中，我不能简单地选择最早的日期、最年轻的时间/最晚日期、最晚时间和 Unix() 秒来比较它们。非常感谢任何建议。

最后，我写了一个时间解析字符串比较模块来检查时间是否在一个范围内。然而，这并不顺利。我有一些悬而未决的问题。我会在这里发布只是为了好玩，但我希望有更好的时间比较方法。

package main

import (
    "strconv"
    "strings"
)

func tryIndex(arr []string, index int, def string) string {
    if index <= len(arr)-1 {
        return arr[index]
    }
    return def
}

/*
 * Takes two strings of format "hh:mm:ss" and compares them.
 * Takes a function to compare individual sections (split by ":").
 * Note: strings can actually be formatted like "h", "hh", "hh:m",
 * "hh:mm", etc. Any missing parts will be added lazily.
 */
func timeCompare(a, b string, compare func(int, int) (bool, bool)) bool {
    aArr := strings.Split(a, ":")
    bArr := strings.Split(b, ":")
    // Catches margins.
    if (b == a) {
        return true
    }
    for i := range aArr {
        aI, _ := strconv.Atoi(tryIndex(aArr, i, "00"))
        bI, _ := strconv.Atoi(tryIndex(bArr, i, "00"))
        res, flag := compare(aI, bI)
        if res {
            return true
        } else if flag { // Needed to catch case where a > b and a is the lower limit
            return false
        }
    }
    return false
}

func timeGreaterEqual(a, b int) (bool, bool) {return a > b, a < b}
func timeLesserEqual(a, b int) (bool, bool) {return a < b, a > b}

/*
 * Returns true for two strings formmated "hh:mm:ss".
 * Note: strings can actually be formatted like "h", "hh", "hh:m",
 * "hh:mm", etc. Any missing parts will be added lazily.
 */
func withinTime(timeRange, time string) bool {
    rArr := strings.Split(timeRange, "-")
    if timeCompare(rArr[0], rArr[1], timeLesserEqual) {
        afterStart := timeCompare(rArr[0], time, timeLesserEqual)
        beforeEnd := timeCompare(rArr[1], time, timeGreaterEqual)
        return afterStart && beforeEnd
    }
    // Catch things like `timeRange := "22:00:00-04:59:59"` which will happen
    // with UTC conversions from local time.
    // THIS IS THE BROKEN PART I BELIEVE
    afterStart := timeCompare(rArr[0], time, timeLesserEqual)
    beforeEnd := timeCompare(rArr[1], time, timeGreaterEqual)
    return afterStart || beforeEnd
}

所以 TLDR，我写了一个 withinTimeRange(range, time) 函数，但它不能完全正常工作。 (事实上​​，大多数情况下，时间范围跨越几天的情况被破坏了。原始部分有效，我只是意识到在从本地转换为 UTC 时需要考虑这一点。)

如果有更好的(最好是内置的)方法，我很想听听!

注意: 举个例子，我用这个函数在 Javascript 中解决了这个问题:

function withinTime(start, end, time) {
    var s = Date.parse("01/01/2011 "+start);
    var e = Date.parse("01/0"+(end=="24:00:00"?"2":"1")+"/2011 "+(end=="24:00:00"?"00:00:00":end));
    var t = Date.parse("01/01/2011 "+time);
    return s <= t && e >= t;
}

但是我真的很想在服务器端做这个过滤器。

最佳答案

使用 time在 Go 中处理时间信息的包。

Time instants can be compared using the Before, After, and Equal methods. The Sub method subtracts two instants, producing a Duration. The Add method adds a Time and a Duration, producing a Time.

Play示例:

package main

import (
    "fmt"
    "time"
)

func inTimeSpan(start, end, check time.Time) bool {
    return check.After(start) && check.Before(end)
}

func main() {
    start, _ := time.Parse(time.RFC822, "01 Jan 15 10:00 UTC")
    end, _ := time.Parse(time.RFC822, "01 Jan 16 10:00 UTC")

    in, _ := time.Parse(time.RFC822, "01 Jan 15 20:00 UTC")
    out, _ := time.Parse(time.RFC822, "01 Jan 17 10:00 UTC")

    if inTimeSpan(start, end, in) {
        fmt.Println(in, "is between", start, "and", end, ".")
    }

    if !inTimeSpan(start, end, out) {
        fmt.Println(out, "is not between", start, "and", end, ".")
    }
}

关于datetime - 如何进行日期/时间比较，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/20924303/