$isoWeek（表达式操作符）

定义

$isoWeek

以 ISO 8601 格式返回周数，范围从 1 到 53。周数从 1 开始，即包含一年中第一个星期四的那个星期（星期一到星期日）。

The $isoWeek expression has the following operator expression syntax:

{ $isoWeek: <dateExpression> }

参数可以是：

• 可解析为日期、时间戳或对象标识符的表达式。

• 具有此格式的文档：

  { date: <dateExpression>, timezone: <tzExpression> }

  字段	说明
  date	应用操作符的日期。<dateExpression> 必须是解析为日期、时间戳或对象标识符的有效表达式。
  timezone	Optional. The timezone of the operation result. <tzExpression> must be a valid expression that resolves to a string formatted as either an Olson Timezone Identifier or a UTC Offset. If no timezone is provided, the result is in UTC. format 示例 Olson Timezone Identifier "America/New_York" "Europe/London" "GMT" UTC Offset +/-[hh]:[mm], e.g. "+04:45" +/-[hh][mm], e.g. "-0530" +/-[hh], e.g. "+03"

行为

{ $isoWeek: { date: new Date("Jan 4, 2016") } }

{ $isoWeek: new Date("2016-01-01") }

{ $isoWeek: {
    date: new Date("August 14, 2011"),
    timezone: "America/Chicago"
} }

{ $isoWeek: ISODate("1998-11-02T00:00:00Z") }

{ $isoWeek: {
    date: ISODate("1998-11-02T00:00:00Z"),
    timezone: "-0500"
} }

{ $isoWeek: "March 28, 1976" }

{ $isoWeek: Date("2016-01-01") }

{ $isoWeek: "2009-04-09" }

例子

名为 deliveries 的集合包含以下文档：

db.deliveries.insertMany( [
   { _id: 1, date: ISODate("2006-10-24T00:00:00Z"), city: "Boston" },
   { _id: 2, date: ISODate("2011-08-18T00:00:00Z"), city: "Detroit" }
] )

以下操作返回每个date字段的周数。

db.deliveries.aggregate( [
  {
    $project: {
      _id: 0,
      city: "$city",
      weekNumber: { $isoWeek: "$date" }
    }
  }
] )

操作返回以下结果：

[
   { city: "Boston", weekNumber: 43 },
   { city: "Detroit", weekNumber: 33 }
]