如何在MongoDB中使用多个条件更新数组
要使用多个条件更新数组，请在MongoDB中使用$push。让我们创建一个包含文档的集合-
> db.demo94.insertOne(
... {
...
... "Details" : [
... {
... "Name" : "Chris",
... "Subject" : []
... },
... {
... "Name" : "David",
... "Subject" : []
... },
... {
... "Name" : "Bob",
... "Subject" : []
... }
... ]
... }
... );
{
"acknowledged" : true,
"insertedId" : ObjectId("5e2d553bb8903cdd865577a9")
}在find()方法的帮助下显示集合中的所有文档-
> db.demo94.find();
这将产生以下输出-
{
"_id" : ObjectId("5e2d553bb8903cdd865577a9"), "Details" : [
{ "Name" : "Chris", "Subject" : [ ] },
{ "Name" : "David", "Subject" : [ ] }, { "Name" : "Bob", "Subject" : [ ] }
]
}以下是在MongoDB中使用多个条件更新数组的查询-
> db.demo94.updateOne(
... {
...
... "Details": { "$elemMatch": { "Name": "David"}}
... },
... {
... "$push": { "Details.$.Subject": { "Subject": "MongoDB" }}
... }
...);
{ "acknowledged" : true, "matchedCount" : 1, "modifiedCount" : 1 }在find()方法的帮助下显示集合中的所有文档-
> db.demo94.find();
这将产生以下输出-
{
"_id" : ObjectId("5e2d553bb8903cdd865577a9"), "Details" : [
{ "Name" : "Chris", "Subject" : [ ] },
{ "Name" : "David", "Subject" : [ { "Subject" : "MongoDB" } ] },
{ "Name" : "Bob", "Subject" : [ ] }
]
}