在 mongoDB 中有條件地 findAndModify

Question

如果promotional值大於我想將其設置為30的credit值，我想更新它，否則我希望它設置為20 。

文檔

    {
        "_id" : "XX",    
        "promotional" : 200,    

    }

代碼

let creditDeduct= 100
let accountId = 'xx'

this.adapter.collection.findAndModify(
    _id = accountId, 
    [["_id", "asc"]], 
    { "$inc": { $cond: { if: { $gte: [ '$promotional', creditDeduct ] }, then: 30, else: 20 }} },
    { "new": true, "upsert": true }, 
    function(error, doc) { 
        if (doc) {
                console.log(doc);
                } 
            if(error){
                console.log(error);
            }
            }
);

錯誤

{ MongoError: Cannot increment with non-numeric argument: {$cond: { if: { $gte: [ "$promotional", 100 ] }, then: 30, else: 20 }}
    at Connection.<anonymous> (/xx/xx/node_modules/mongodb/lib/core/connection/pool.js:466:61)
    at Connection.emit (events.js:198:13)
    at processMessage (/xx/xx/node_modules/mongodb/lib/core/connection/connection.js:364:10)
    at Socket.<anonymous> (/xx/xx/node_modules/mongodb/lib/core/connection/connection.js:533:15)
    at Socket.emit (events.js:198:13)
    at addChunk (_stream_readable.js:288:12)
    at readableAddChunk (_stream_readable.js:269:11)
    at Socket.Readable.push (_stream_readable.js:224:10)
    at TCP.onStreamRead [as onread] (internal/stream_base_commons.js:94:17)   ok: 0,   errmsg:    'Cannot increment with non-numeric argument: {$cond: { if: { $gte: [ "$promotional", 100 ] }, then: 30, else: 20 }}',   code: 14,   codeName: 'TypeMismatch',   name: 'MongoError',   [Symbol(mongoErrorContextSymbol)]: {} }

Answer 1

當你想設置值時，你需要使用set

var credit= 100
db.collection.updateMany({"promotional":{$gt:credit}},{$set:{"promotional":20}})
db.collection.updateMany({"promotional":{$lte:credit}},{$set:{"promotional":30}})

此外， $inc將僅適用於數字數據類型。 你能檢查promotional值是number而不是string嗎？

在 Mongo Compass 中，您可以單擊編輯按鈕來設置其數據類型。

請參閱下面的示例，我將其設置為 int64：