【发布时间】：2020-07-10 16:00:30
【问题描述】：
您好，我正在尝试使用 nodejs 更新 mongodb 中的单个数组项。我在 mongodb 中的数据结构是这样的：
{
"_id": "5e818db59cedd232d83c66cb",
"project": "projectX",
"version": 1,
"salesChannel": "channel42",
"country": "Austria",
"book": true,
"categories": [
{
"pieceItems": [
{
"category": "pieceItems",
"identifier": "1.1",
"registrationHints": "Scan the barcode OR register the itemNumber manually",
"variant": "Tax-Group 19%",
"additionalHints": "optionally provided"
}
],
},
{
"weightItems": [
{
"category": "weightItems",
"identifier": "2.1",
"registrationHints": "Scan the barcode OR register the itemNumber manually",
"variant": "Tax-Group 19%",
"additionalHints": "optionally provided"
},
{
"category": "weightItems",
"identifier": "2.2",
"registrationHints": "Scan the barcode OR register the itemNumber manually",
"variant": "Tax-Group 19%",
"additionalHints": "optionally provided"
}
],
}
]
}
这是我尝试过的代码，但我的数据库中没有任何变化：
exports.editCategoryInBook = function (body, project, salesChannelName, country) {
mongoClient.connect(mongoUrl, async (err, client) => {
assert.equal(null, err)
const db = client.db(dbName)
var categoryName = Object.keys(body)[0]
var updateCategory = `categories.$.${categoryName}`
var categoryValue = body[categoryName]
console.log(`$set: { ${updateCategory}: categoryValue }`)
db.collection(project).updateOne({
"book": true,
"salesChannel": salesChannelName,
"country": country
}, {
$set: { [updateCategory]: categoryValue },
$currentDate: { lastModified: true }
})
client.close()
})
return new Promise(function (resolve, reject) {
resolve();
});
}
这是传递给函数的主体变量：
{
"pieceItems": [
{
"category": "Piece Item",
"identifier": 1.11,
"registrationHints": "Scan the barcode OR register the itemNumber manually; some more hints could follow",
"variant": "Tax-Group 19%",
"additionalHints": "some string hint to give bonus information about this item",
"name": "Buntsteinputz 8508",
"EAN": 4003498690070,
"PLU": 3822584,
"price": "51,95€"
},
{
"category": "Piece Item",
"identifier": 1.2,
"registrationHints": "Scan the barcode OR register the itemNumber manually; some more hints could follow",
"variant": "Tax-Group 7%",
"additionalHints": "some string hint to give bonus information about this item",
"name": "Buntsteinputz 8508",
"EAN": 4003498690070,
"PLU": 3822584,
"price": "51,95€"
}
]
}
我从 console.log 得到以下输出：
$set: { categories.$.pieceItems: categoryValue }
我得到以下错误：
MongoError: The positional operator did not find the match needed from the query.
at Function.create (C:\Users\rkrause\node_modules\mongodb\lib\core\error.js:43:12)
at toError (C:\Users\rkrause\node_modules\mongodb\lib\utils.js:149:22)
at C:\Users\rkrause\node_modules\mongodb\lib\operations\common_functions.js:376:39
at C:\Users\rkrause\node_modules\mongodb\lib\core\connection\pool.js:404:18
at processTicksAndRejections (internal/process/task_queues.js:82:9)
【问题讨论】：
-
使用
"param": true的原因是什么？ -
@Ramesh 哦谢谢！我忘了把它改成
"book": true并更新了另一个文件.. 那是错误 -
很高兴我能帮上忙。每个人都会犯这些愚蠢的错误，只有其他人才能发现它们，因为它们是逐行进行的，而我们在检查自己的代码时不会这样做:)。
-
您是否要添加其他字段（EAN、PLU、价格）到
pieceItems数组中的现有子文档。 -
@prasad_ 是的，如果正文有差异，我想更新整个pieceItems Array