mongoDB-获取子字符串&；在分组阶段将字符串转换为数字

我试图通过MongoDB中的聚合计算员工的工资总额，问题是工资以货币符号<代码>$为准，无法在组中获得总额

示例数据库条目：

{  
"_id" : ObjectId("5e2f408b1548343a74dce68a"),  
"employee_first_name" : "Gwenaëlle",  
"employee_last_name" : "Shawley",  
"department" : "Product Management",  
"salary" : "$205223.43",  
"years_in_job" : 17,  
"dob" : "4/12/1980",  
"childrenId" : [  
ObjectId("5e2da031c71c0b0f54e35236"),  
ObjectId("5e2da031c71c0b0f54e35234"),  
ObjectId("5e2da031c71c0b0f54e35235"),  
],  
"updatedAt" : ISODate("2020-02-06T16:47:29.208Z")  
}

用MongoDB编写的查询：

aggregation query:
db.getCollection('employee_details')
    .aggregate([
        { $match: { department: "Product Management" } },
        {
            $group:
            {
                "_id": "$years_in_job",
                total: { $sum: '$salary' }
            }
        }
    ])

---

我建议您先删除工资中的$，然后在计算完总值后对其进行预处理或连接。

我建议您先删除工资中的$，然后在计算完总值后对其进行预处理或连接。

尝试此查询：

db.getCollection('employee_details')
    .aggregate([
        { $match: { department: "Product Management" } },
        {
            $group:
            {
                "_id": "$years_in_job",
                /** get substring of salary which removes $ from string & then convert it into double for sum */
                total: { $sum: { $toDouble: { $substr: ["$salary", 1, -1] } } }
            }
        }
    ])

测试：

尝试以下查询：

db.getCollection('employee_details')
    .aggregate([
        { $match: { department: "Product Management" } },
        {
            $group:
            {
                "_id": "$years_in_job",
                /** get substring of salary which removes $ from string & then convert it into double for sum */
                total: { $sum: { $toDouble: { $substr: ["$salary", 1, -1] } } }
            }
        }
    ])

---

测试：

它工作正常还是仍然存在问题？如果确实如此，请接受这一点&您的问题将以一个有效的答案结束：-）它是否有效或仍然存在问题？如果确实如此，请接受这一点&您的问题将以有效答案结束：-）