MongoDB - aggregation with where clause and parsing string column to number-CodePudding

I am trying to code up something using an SDK that uses mongodb behind the scenes. The backend has a collection, that stores number values as a string.

Now I want query that collection and check if the value in that string column is greaterThan or lessThan a given value.

Since the column is of type string, I dont know how I can write an aggregation that parses this string value to a number value.

Example

collection { balance: string }

My goal, query collection WHERE balance >= someValue

CodePudding user response：

I believe you are looking for somehting like this:

model.aggregate([
    {
        '$addFields': {
            'decimalBalance': {
                '$toDecimal': '$balance'
            }
        }
    }, {
        '$match': {
            'decimalBalance': {
                '$gte': value
            }
        }
    }
])

You can $unset or not $project the extra Field, I don't know how to do it without the extra field.

For reference look here: