使用MongoDB将数组内的多个条件匹配吗？
为此，请将聚合框架与$elemMatch运算符配合使用。首先让我们创建一个包含文档的集合-
> db.matchMultipleCriteriaDemo.insertOne({
"EmployeeDetails": [
{"EmployeeName": "Chris", "Salary": 45000, "Language":"Java"},
{"EmployeeName": "Robert", "Salary": 41000, "Language":"Python"}
]
});
{
"acknowledged" : true,
"insertedId" : ObjectId("5cea3bf0ef71edecf6a1f689")
}
> db.matchMultipleCriteriaDemo.insertOne({
"EmployeeDetails": [
{"EmployeeName": "David", "Salary": 55000, "Language":"C++"},
{"EmployeeName": "Bob", "Salary": 61000, "Language":"C"}
]
});
{
"acknowledged" : true,
"insertedId" : ObjectId("5cea3bf1ef71edecf6a1f68a")
}以下是在find()方法的帮助下显示集合中所有文档的查询-
> db.matchMultipleCriteriaDemo.find().pretty();
这将产生以下输出-
{
"_id" : ObjectId("5cea3bf0ef71edecf6a1f689"),
"EmployeeDetails" : [
{
"EmployeeName" : "Chris",
"Salary" : 45000,
"Language" : "Java"
},
{
"EmployeeName" : "Robert",
"Salary" : 41000,
"Language" : "Python"
}
]
}
{
"_id" : ObjectId("5cea3bf1ef71edecf6a1f68a"),
"EmployeeDetails" : [
{
"EmployeeName" : "David",
"Salary" : 55000,
"Language" : "C++"
},
{
"EmployeeName" : "Bob",
"Salary" : 61000,
"Language" : "C"
}
]
}以下是匹配数组中多个条件的查询-
> db.matchMultipleCriteriaDemo.aggregate({ "$match": { "EmployeeDetails": { "$elemMatch": { "EmployeeName": "Bob", "Language":"C" } } }} ).pretty();这将产生以下输出-
{
"_id" : ObjectId("5cea3bf1ef71edecf6a1f68a"),
"EmployeeDetails" : [
{
"EmployeeName" : "David",
"Salary" : 55000,
"Language" : "C++"
},
{
"EmployeeName" : "Bob",
"Salary" : 61000,
"Language" : "C"
}
]
}