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Date()

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Date()

Returns a date either as a string or as a Date object.以字符串或Date对象的形式返回日期。

  • Date() returns the current date as a string in mongosh.mongosh中以字符串形式返回当前日期。
  • new Date() returns the current date as a Date object. mongosh wraps the Date object with the ISODate helper. 将当前日期作为Date对象返回。mongosh使用ISODate辅助对象包装Date对象。The ISODate is in UTC.ISODateUTC为单位。

You can specify a particular date by passing an ISO-8601 date string with a year within the inclusive range 0 through 9999 to the new Date() constructor or the ISODate() function. 您可以通过将年份在09999之间的ISO-8601日期字符串传递给new Date()构造函数或ISODate()函数来指定特定日期。These functions accept the following formats:这些函数接受以下格式:

  • new Date("<YYYY-mm-dd>") returns the ISODate with the specified date.返回具有指定日期的ISODate
  • new Date("<YYYY-mm-ddTHH:MM:ss>") specifies the datetime in the client's local timezone and returns the ISODate with the specified datetime in UTC.指定客户端本地时区中的日期时间,并返回指定日期时间(UTC)的ISODate
  • new Date("<YYYY-mm-ddTHH:MM:ssZ>") specifies the datetime in UTC and returns the ISODate with the specified datetime in UTC.指定以UTC表示的日期时间,并返回以UTC表示指定日期时间的ISODate
  • new Date(<integer>) specifies the datetime as milliseconds since the UNIX epoch (Jan 1, 1970), and returns the resulting ISODate instance.将日期时间指定为自UNIX纪元(1970年1月1日)以来的毫秒,并返回生成的ISODate实例。

Behavior行为

Internally, Date objects are stored as a signed 64-bit integer representing the number of milliseconds since the Unix epoch (Jan 1, 1970).在内部,Date对象存储为一个带符号的64位整数,表示自Unix epoch(1970年1月1日)以来的毫秒数。

Not all database operations and drivers support the full 64-bit range. You may safely work with dates with years within the inclusive range 0 through 9999.并非所有数据库操作和驱动程序都支持完整的64位范围。您可以安全地使用年份在09999之间的日期。

Examples实例

Use Date in a Query在查询中使用日期

If no document with _id equal to 1 exists in the products collection, the following operation inserts a document with the field dateAdded set to the current date:如果products集合中不存在_id等于1的文档,则以下操作将插入字段dateAdded设置为当前日期的文档:

db.products.updateOne(
{ _id: 1 },
{
$set: { item: "apple" },
$setOnInsert: { dateAdded: new Date() }
},
{ upsert: true }
)
Tip

See also: 另请参阅:

Return Date as a String字符串形式的返回日期

To return the date as a string, use the Date() method, as in the following example:要将日期作为字符串返回,请使用Date()方法,如下例所示:

var myDateString = Date();

Return Date as Date Object返回日期作为Date对象

mongosh wraps objects of Date type with the ISODate helper; however, the objects remain of type Date.mongosh使用ISODate辅助对象包装Date类型的对象;但是,对象仍然是Date类型。

The following example uses new Date() to return Date object with the specified UTC datetime.以下示例使用new Date()返回具有指定UTC日期时间的Date对象。

var myDate = new Date("2016-05-18T16:00:00Z");
Tip

See also: 另请参阅:

Insert and Return ISODate Objects插入并返回ISODate对象

You can specify dates as ISODate objects.可以将日期指定为ISODate对象。

The following example creates a cakeSales collection with ISODate objects in the orderDate field:以下示例在orderDate字段中创建了一个带有ISODate对象的cakeSales集合:

db.cakeSales.insertMany( [
{ _id: 0, type: "chocolate", orderDate: new ISODate("2020-05-18T14:10:30Z") },
{ _id: 1, type: "strawberry", orderDate: new ISODate("2021-03-20T11:30:05Z") },
{ _id: 2, type: "vanilla", orderDate: new ISODate("2021-01-15T06:31:15Z") }
] )

The following example returns documents where the orderDate is less than the ISODate specified in the $lt operator:以下示例返回orderDate小于$lt运算符中指定的ISODate的文档:

db.cakeSales.find( { orderDate: { $lt: ISODate("2021-02-25T10:03:46.000Z") } } )

Example output:示例输出:

[
{
_id: 0,
type: 'chocolate',
orderDate: ISODate("2020-05-18T14:10:30.000Z")
},
{
_id: 2,
type: 'vanilla',
orderDate: ISODate("2021-01-15T06:31:15.000Z")
}
]