查询MongoDB的子集以获取记录
您可以使用$all运算符。首先让我们创建一个包含文档的集合-
> db.subsetOfAnArrayDemo.insertOne({"StudentProgrammingSkills":
["Java","MongoDB","MySQL","C++","Data Structure","Algorithm","Python","Oracle","SQL Server"]});
{
"acknowledged" : true,
"insertedId" : ObjectId("5cb9d1e1895c4fd159f80804")
}以下是在find()方法的帮助下显示集合中所有文档的查询-
> db.subsetOfAnArrayDemo.find().pretty();
这将产生以下输出-
{
"_id" : ObjectId("5cb9d1e1895c4fd159f80804"),
"StudentProgrammingSkills" : [
"Java",
"MongoDB",
"MySQL",
"C++",
"Data Structure",
"Algorithm",
"Python",
"Oracle",
"SQL Server"
]
}以下是获取数组子集的查询-
> db.subsetOfAnArrayDemo.find({ StudentProgrammingSkills:
{ $all: [ 'MongoDB', 'MySQL' ] } } ).pretty();这将产生以下输出-
{
"_id" : ObjectId("5cb9d1e1895c4fd159f80804"),
"StudentProgrammingSkills" : [
"Java",
"MongoDB",
"MySQL",
"C++",
"Data Structure",
"Algorithm",
"Python",
"Oracle",
"SQL Server"
]
}热门推荐
10 新年门口花束祝福语简短
11 盘锦结婚祝福语大全简短
12 父母生日祝福语 简短独特
13 家庭恩爱祝福语简短英文
14 高考俄语祝福语大全简短
15 虎年祝福语 诗句唯美简短
16 生日婚礼祝福语简短精辟
17 虎年喝酒拜年祝福语简短
18 教师闺蜜祝福语简短