MongoDB:在多种条件下更新数组元素

Question

各位同事，下午好！我正在为一些问题而挣扎。我使用的是MongoDB 4.4.4。我的任务是这样的：

1. 存在一组元素methods[].subcategories[].actions[]。请注意，所有对象都是数组，它们可能不存在。actions[]阵列的元素由_id和title字段组成
2. 需要通过元素的字段actions.title找到recordId的实际值，并将其写入actions数组的元素

当前值列表：

0af4cd2e-78cb-109b-8178-d5a7ba0e0012, Inspection
0af4cd2e-78cb-109b-8178-d5a7ba130014, Screening
0af4cd2e-78cb-109b-8178-d5a7ba170016, Poll
0af4cd2e-78cb-109b-8178-d5a7ba1b0018, Getting written explanations
0af4cd2e-78cb-109b-8178-d5a7ba1e001a, Request for documents
0af4cd2e-78cb-109b-8178-d5a7ba21001c, Sampling (samples)
0af4cd2e-78cb-109b-8178-d5a7ba23001e, Instrumental examination
0af4cd2e-78cb-109b-8178-d5a7ba260020, Test
0af4cd2e-78cb-109b-8178-d5a7ba2b0022, Expertise
0af4cd2e-78cb-109b-8178-d5a7ba2d0024, Experiment
3b7205c1-8282-4b63-8121-b82aacd7ca67, Request for documents that, in accordance with the mandatory requirements, must be located at the location (carrying out activities) of the controlled person (its branches, representative offices, separate structural divisions) or the object of control

我写了以下代码：

db.getSiblingDB("ervk_core").getCollection("supervision1").updateMany(
{},
{
"$set": {
"methods.subcategories.actions.$[elem1]._id": "0af4cd2e-78cb-109b-8178-d5a7ba0e0012",
"methods.subcategories.actions.$[elem2]._id": "0af4cd2e-78cb-109b-8178-d5a7ba0e0014",
"methods.subcategories.actions.$[elem3]._id": "0af4cd2e-78cb-109b-8178-d5a7ba0e0016",
"methods.subcategories.actions.$[elem4]._id": "0af4cd2e-78cb-109b-8178-d5a7ba0e0018",
"methods.subcategories.actions.$[elem5]._id": "0af4cd2e-78cb-109b-8178-d5a7ba0e001a",
"methods.subcategories.actions.$[elem6]._id": "0af4cd2e-78cb-109b-8178-d5a7ba0e001c",
"methods.subcategories.actions.$[elem7]._id": "0af4cd2e-78cb-109b-8178-d5a7ba0e001e",
"methods.subcategories.actions.$[elem8]._id": "0af4cd2e-78cb-109b-8178-d5a7ba260020",
"methods.subcategories.actions.$[elem9]._id": "0af4cd2e-78cb-109b-8178-d5a7ba260022",
"methods.subcategories.actions.$[elem10]._id": "0af4cd2e-78cb-109b-8178-d5a7ba260024",
"methods.subcategories.actions.$[elem11]._id": "3b7205c1-8282-4b63-8121-b82aacd7ca67",
}
},
{
"arrayFilters": [
{
"elem1.title": "Inspection",
},
{
"elem2.title": "Search",
},
{
"elem3.title": "Poll",
},
{
"elem4.title": "Receipt of Written Explanations",
},
{
"elem5.title": "Retrieval of Documents",
},
{
"elem6.title": "Sampling (samples)",
},
{
"elem7.title": "Instrumental examination",
},
{
"elem8.title": "Trial",
},
{
"elem9.title": "Expertise",
},
{
"elem10.title": "Experiment",
},
{
"elem11.title": "Request for documents that, in accordance with the mandatory requirements, must be located at the location (carrying out activities) of the controlled person (its branches, representative offices, separate structural divisions) or the object of control",
}
]
}
);

然而，它给出了错误"The path 'methods.subcategories.actions' must exist in the document in order to apply array updates."。我理解为什么会发生这种情况——因为没有actions[]数组。但是，我如何解释methods[].subcategories[].actions[]阵列可能丢失的事实呢。我的代码写对了吗？否则我已经有点困惑了。提前感谢！

Answer 1

您可以做的是向方法和子类别对象添加数组过滤器检查，以查看嵌套数组是否存在，这将解决您的问题，因为Mongo不会继续检查嵌套条件，以防它们不存在。以下是您的操作方法：

db.collection.updateMany(
{
"methods.subcategories.actions": {
$exists: true
}
},
{
"$set": {
"methods.$[methodElem].subcategories.$[subCatElem].actions.$[elem1]._id": "0af4cd2e-78cb-109b-8178-d5a7ba0e0012",
"methods.$[methodElem].subcategories.$[subCatElem].actions.$[elem2]._id": "0af4cd2e-78cb-109b-8178-d5a7ba0e0014",
"methods.$[methodElem].subcategories.$[subCatElem].actions.$[elem3]._id": "0af4cd2e-78cb-109b-8178-d5a7ba0e0016",
"methods.$[methodElem].subcategories.$[subCatElem].actions.$[elem4]._id": "0af4cd2e-78cb-109b-8178-d5a7ba0e0018",
"methods.$[methodElem].subcategories.$[subCatElem].actions.$[elem5]._id": "0af4cd2e-78cb-109b-8178-d5a7ba0e001a",
"methods.$[methodElem].subcategories.$[subCatElem].actions.$[elem6]._id": "0af4cd2e-78cb-109b-8178-d5a7ba0e001c",
"methods.$[methodElem].subcategories.$[subCatElem].actions.$[elem7]._id": "0af4cd2e-78cb-109b-8178-d5a7ba0e001e",
"methods.$[methodElem].subcategories.$[subCatElem].actions.$[elem8]._id": "0af4cd2e-78cb-109b-8178-d5a7ba260020",
"methods.$[methodElem].subcategories.$[subCatElem].actions.$[elem9]._id": "0af4cd2e-78cb-109b-8178-d5a7ba260022",
"methods.$[methodElem].subcategories.$[subCatElem].actions.$[elem10]._id": "0af4cd2e-78cb-109b-8178-d5a7ba260024",
"methods.$[methodElem].subcategories.$[subCatElem].actions.$[elem11]._id": "3b7205c1-8282-4b63-8121-b82aacd7ca67"
}
},
{
"arrayFilters": [
{
"methodElem.subcategories": {
$exists: true
}
},
{
"subCatElem.actions": {
$exists: true
}
},
{
"elem1.title": "Inspection"
},
{
"elem2.title": "Search"
},
{
"elem3.title": "Poll"
},
{
"elem4.title": "Receipt of Written Explanations"
},
{
"elem5.title": "Retrieval of Documents"
},
{
"elem6.title": "Sampling (samples)"
},
{
"elem7.title": "Instrumental examination"
},
{
"elem8.title": "Trial"
},
{
"elem9.title": "Expertise"
},
{
"elem10.title": "Experiment"
},
{
"elem11.title": "Request for documents that, in accordance with the mandatory requirements, must be located at the location (carrying out activities) of the controlled person (its branches, representative offices, separate structural divisions) or the object of control"
}
]
})

Mongo游乐场

我还将更新查询更改为只忽略文档，没有嵌套操作，这只是为了节省时间。