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法律研究如何在 MongoDB 中更新子文件陣列？
要更新，請使用 update() 和 $set。我們建立一個包含文件的集合 -
>db.demo134.insertOne({"EmployeeId":101,"EmployeeDetails":[{"EmployeeName":"Chris","EmployeeAge":27},{"EmployeeName":"Bob","EmployeeAge":28}]});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e319b2f68e7f832db1a7f7c")
}
>db.demo134.insertOne({"EmployeeId":102,"EmployeeDetails":[{"EmployeeName":"David","EmployeeAge":24},{"EmployeeName":"Carol","EmployeeAge":29}]});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e319b4468e7f832db1a7f7d")
}使用 find() 方法從集合中顯示所有文件 -
> db.demo134.find().pretty();
這將生成以下輸出 -
{
"_id" : ObjectId("5e319b2f68e7f832db1a7f7c"),
"EmployeeId" : 101,
"EmployeeDetails" : [
{
"EmployeeName" : "Chris",
"EmployeeAge" : 27
},
{
"EmployeeName" : "Bob",
"EmployeeAge" : 28
}
]
}
{
"_id" : ObjectId("5e319b4468e7f832db1a7f7d"),
"EmployeeId" : 102,
"EmployeeDetails" : [
{
"EmployeeName" : "David",
"EmployeeAge" : 24
},
{
"EmployeeName" : "Carol",
"EmployeeAge" : 29
}
]
}以下是更新 MongoDB 中子文件陣列的查詢 -
> db.demo134.update(
... {
... "EmployeeId":101,
... "EmployeeDetails.EmployeeName":"Chris"
... },
... {
... $set: {
... "EmployeeDetails.$.EmployeeName" : "Robert"
... }
... }
... );
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })使用 find() 方法從集合中顯示所有文件 -
> db.demo134.find().pretty();
這將生成以下輸出 -
{
"_id" : ObjectId("5e319b2f68e7f832db1a7f7c"),
"EmployeeId" : 101,
"EmployeeDetails" : [
{
"EmployeeName" : "Robert",
"EmployeeAge" : 27
},
{
"EmployeeName" : "Bob",
"EmployeeAge" : 28
}
]
}
{
"_id" : ObjectId("5e319b4468e7f832db1a7f7d"),
"EmployeeId" : 102,
"EmployeeDetails" : [
{
"EmployeeName" : "David",
"EmployeeAge" : 24
},
{
"EmployeeName" : "Carol",
"EmployeeAge" : 29
}
]
}
更新日期： 31-3-2020
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