如何查找与MongoDB查询中的数组条目完全相同的文档？
为此，请使用$all运算符。首先让我们创建一个包含文档的集合-
>db.findDocumentExactlySameInArrayDemo.insertOne({"TechnicalSubjects":["C++","Java","MongoDB"]});
{
"acknowledged" : true,
"insertedId" : ObjectId("5cd69a5f57806ebf1256f12e")
}
>db.findDocumentExactlySameInArrayDemo.insertOne({"TechnicalSubjects":["MySQL","Java","MongoDB"]});
{
"acknowledged" : true,
"insertedId" : ObjectId("5cd69ac057806ebf1256f12f")
}
>db.findDocumentExactlySameInArrayDemo.insertOne({"TechnicalSubjects":["C#","Python","MongoDB"]});
{
"acknowledged" : true,
"insertedId" : ObjectId("5cd69ad457806ebf1256f130")
}
>db.findDocumentExactlySameInArrayDemo.insertOne({"TechnicalSubjects":["MySQL","C","MongoDB"]});
{
"acknowledged" : true,
"insertedId" : ObjectId("5cd69adf57806ebf1256f131")
}以下是在find()方法的帮助下显示集合中所有文档的查询-
> db.findDocumentExactlySameInArrayDemo.find().pretty();
这将产生以下输出-
{
"_id" : ObjectId("5cd69a5f57806ebf1256f12e"),
"TechnicalSubjects" : [
"C++",
"Java",
"MongoDB"
]
}
{
"_id" : ObjectId("5cd69ac057806ebf1256f12f"),
"TechnicalSubjects" : [
"MySQL",
"Java",
"MongoDB"
]
}
{
"_id" : ObjectId("5cd69ad457806ebf1256f130"),
"TechnicalSubjects" : [
"C#",
"Python",
"MongoDB"
]
}
{
"_id" : ObjectId("5cd69adf57806ebf1256f131"),
"TechnicalSubjects" : [
"MySQL",
"C",
"MongoDB"
]
}以下是查询以查找具有与查询中完全相同的数组条目的文档-
> db.findDocumentExactlySameInArrayDemo.find({"TechnicalSubjects": { "$all": ["MySQL","Java","MongoDB"] }});这将产生以下输出-
{ "_id" : ObjectId("5cd69ac057806ebf1256f12f"), "TechnicalSubjects" : [ "MySQL", "Java", "MongoDB" ] }