Question

是否有任何逻辑作为javascript替换（/ [^ \ d。] / g，''）方法。只获取字符串的数值。

从字符串中获取整数

示例文档：

{
    "_id" : "1",
    "planName" : "Options Silver 1431B"
}
{
    "_id" : "1",
    "planName" : "Options Silver 1431A"
}
{
    "_id" : "1",
    "planName" : "myOptions 1431A"
}
{
    "_id" : "1",
    "planName" : "myOptions 1431"
}
{
    "_id" : "1",
    "planName" : "myOptions 1431A",

}

结果：

   {
        "_id" : "1",
        plan_id: "1431"
   },
   {
        "_id" : "1",
        plan_id: "1431"
   },
   {
        "_id" : "1",
        plan_id: "1431"
   },
   {
        "_id" : "1",
        plan_id: "1431"
   },
   {
       "_id" : "1",
        plan_id: "1431"
   }

Answer 1

您可以使用聚合框架分三步完成：

使用$map和$range $substrCP将您的字符串转换为字符数组
使用$filter仅保留数字值（"0" - "9"）

使用$reduce将它们连成一个字符串

db.col.aggregate([
    {
        $addFields: {
            chars: {
                "$map":{
                    "input":{
                        "$range":[
                            0,
                            {
                                "$strLenCP":"$planName"
                            }
                        ]
                    },
                    "in":{
                        "$substrCP":[
                            "$planName",
                            "$$this",
                            1
                        ]
                    }
                }
            }
        }
    },
    {
        $project: {
            numbers: {
                $filter: {
                 input: "$chars",
                 as: "char",
                 cond: { $and: [
                    { $gte: [ "$$char", "0" ] },
                    { $lte: [ "$$char", "9" ] }
                  ] }
              }
            }
        }
    },
    {
        $project: {
            plan_id: { 
                $reduce: {
                  input: "$numbers",
                  initialValue: "",
                  in: { $concat : ["$$value", "$$this"] }
                }
            }
        }
    }
])

Mongodb：项目只从字符串中获取数值

1 个答案: