在MongoDB中将数据插入内部数组？
您可以为此使用$addToSet运算符。首先让我们创建一个包含文档的集合-
> db.insertDataIntoArrayDemo.insertOne(
{
"UserDetails":[
{
"UserId" :"user121",
"userGroupMessage":[]
},
{
"UserId" :"user221",
"userGroupMessage":["Cool","Good Morning"]
}
]
}
);
{
"acknowledged" : true,
"insertedId" : ObjectId("5cd694e157806ebf1256f128")
}以下是在find()方法的帮助下显示集合中所有文档的查询-
> db.insertDataIntoArrayDemo.find().pretty();
这将产生以下输出-
{
"_id" : ObjectId("5cd694e157806ebf1256f128"),
"UserDetails" : [
{
"UserId" : "user121",
"userGroupMessage" : [ ]
},
{
"UserId" : "user221",
"userGroupMessage" : [
"Cool",
"Good Morning"
]
}
]
}以下是将数据插入MongoDB的内部数组中的查询-
> db.insertDataIntoArrayDemo.update({"UserDetails.UserId":"user121"},
{"$addToSet":{"UserDetails.$.userGroupMessage":"Hello"}});
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })让我们再次检查文档-
> db.insertDataIntoArrayDemo.find().pretty();
这将产生以下输出-
{
"_id" : ObjectId("5cd694e157806ebf1256f128"),
"UserDetails" : [
{
"UserId" : "user121",
"userGroupMessage" : [
"Hello"
]
},
{
"UserId" : "user221",
"userGroupMessage" : [
"Cool",
"Good Morning"
]
}
]
}