使用MongoDB搜索与数组中的第一项匹配的文档吗？
首先让我们创建一个包含文档的集合-
> db.matchingFirstItemInTheArrayDemo.insertOne(
{
"ClientDetails": [
{
"ClientName": "Larry",
"ClientAge":28
}
]
}
);
{
"acknowledged" : true,
"insertedId" : ObjectId("5cd7a5d26d78f205348bc636")
}
> db.matchingFirstItemInTheArrayDemo.insertOne(
{
"ClientDetails": [
{
"ClientName": "Chris",
"ClientAge":56,
}
]
}
);
{
"acknowledged" : true,
"insertedId" : ObjectId("5cd7a5f56d78f205348bc637")
}
> db.matchingFirstItemInTheArrayDemo.insertOne(
{
"ClientDetails": [
{
"ClientName": "Robert",
"ClientAge":46,
}
]
}
);
{
"acknowledged" : true,
"insertedId" : ObjectId("5cd7a6076d78f205348bc638")
}以下是在find()方法的帮助下显示集合中所有文档的查询-
> db.matchingFirstItemInTheArrayDemo.find().pretty();
这将产生以下输出-
{
"_id" : ObjectId("5cd7a5d26d78f205348bc636"),
"ClientDetails" : [
{
"ClientName" : "Larry",
"ClientAge" : 28
}
]
}
{
"_id" : ObjectId("5cd7a5f56d78f205348bc637"),
"ClientDetails" : [
{
"ClientName" : "Chris",
"ClientAge" : 56
}
]
}
{
"_id" : ObjectId("5cd7a6076d78f205348bc638"),
"ClientDetails" : [
{
"ClientName" : "Robert",
"ClientAge" : 46
}
]
}以下是搜索匹配数组中第一项的文档的查询-
> db.matchingFirstItemInTheArrayDemo.find({"ClientDetails.0.ClientName":"Chris"});这将产生以下输出-
{ "_id" : ObjectId("5cd7a5f56d78f205348bc637"), "ClientDetails" : [ { "ClientName" : "Chris", "ClientAge" : 56 } ] }