$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 $divide expression has the following syntax:$divide表达式语法如下：

{ $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.第一个参数是被除数，第二个参数是除数；即，第一参数除以第二参数。

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

Examples示例

Consider a planning collection with the following documents:考虑包含以下文件的planning集合：

{ "_id" : 1, "name" : "A", "hours" : 80, "resources" : 7 },
{ "_id" : 2, "name" : "B", "hours" : 40, "resources" : 4 }

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

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

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

{ "_id" : 1, "name" : "A", "workdays" : 10 }
{ "_id" : 2, "name" : "B", "workdays" : 5 }