$divide (aggregation)

Definition定义

$divide

Divides one number by another and returns the result. 将一个数字除以另一个数字并返回结果。Pass the arguments to $divide in an array.将参数传递给数组中的$divide。

The $divide expression has the following syntax:$diver表达式具有以下语法：

{ $divide: [ <expression1>, <expression2> ] }

The first argument is the dividend, and the second argument is the divisor; i.e. the first argument is divided by the second argument.第一个自变量是被除数，第二个自变量是除数；第一个论点除以第二个论点。

The arguments can be any valid expression as long as they resolve to numbers. For more information on expressions, see Expressions.参数可以是任何有效的表达式，只要它们解析为数字即可。有关表达式的详细信息，请参阅表达式。

Examples实例

Consider a conferencePlanning collection with the following documents:考虑一个包含以下文档的conferencePlanning集合：

db.conferencePlanning.insertMany( [
   { "_id" : 1, "city" : "New York", "hours" : 80, "tasks" : 7 },
   { "_id" : 2, "city" : "Singapore", "hours" : 40, "tasks" : 4 }
] )

The following aggregation uses the $divide expression to divide the hours field by a literal 8 to compute the number of work days:以下聚合使用$dive表达式将hours字段除以文字8来计算工作天数：

db.planning.aggregate(
   [
     { $project: { city: 1, workdays: { $divide: [ "$hours", 8 ] } } }
   ]
)

The operation returns the following results:该操作返回以下结果：

{ "_id" : 1, "city" : "New York", "workdays" : 10 }
{ "_id" : 2, "city" : "Singapore", "workdays" : 5 }