鉴于一个具有值的数组,如何找到匹配 MongoDB 查询的文档?
对于特定文档,请使用 MongoDB $in。让我们创建一个包含文档的集合 −
> db.demo511.insertOne({"ListOfProject":["Library Management System","Hospital
Management System"]});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e88473a987b6e0e9d18f585")
}
> db.demo511.insertOne({"ListOfProject":["Online Web Tracking","Library Management
System"]});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e884751987b6e0e9d18f586")
}
> db.demo511.insertOne({"ListOfProject":["Online Shopping Cart","Hospital Management
System"]});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e884776987b6e0e9d18f587")
}借助 find() 方法显示集合中的所有文档 −
> db.demo511.find();
这将产生以下输出 −
{ "_id" : ObjectId("5e88473a987b6e0e9d18f585"), "ListOfProject" : [ "Library Management
System", "Hospital Management System" ] }
{ "_id" : ObjectId("5e884751987b6e0e9d18f586"), "ListOfProject" : [ "Online Web Tracking",
"Library Management System" ] }
{ "_id" : ObjectId("5e884776987b6e0e9d18f587"), "ListOfProject" : [ "Online Shopping Cart",
"Hospital Management System" ] }以下是对查询匹配文档的查询 −
> db.demo511.find({ "ListOfProject":{$in:["Hospital Management System","Online Shopping Cart"]}});这将产生以下输出 −
{ "_id" : ObjectId("5e88473a987b6e0e9d18f585"), "ListOfProject" : [ "Library Management
System", "Hospital Management System" ] }
{ "_id" : ObjectId("5e884776987b6e0e9d18f587"), "ListOfProject" : [ "Online Shopping Cart",
"Hospital Management System" ] }
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