mongodb常用语法

// Employee表
{
"_id" : "9e794fb9-12dc-457c-8c5a-69fe45c57685",
"No" : 2018090821,
"Name" : "Kelly",
"Age" : 18,
"Addresses":[
{"Type" : "Home", "Location" : "Beijing"},
{"Type" : "Office", "Location" : "Beijing"}
]
}// 分页过滤查找
db.Employee.aggregate([
{ $match:{"Name":"Kelly"}},
{ $project:{"Name":1, "Age":1}},
{ $sort:{"Age":1}},
{ $skip:1000},
{ $limit:30}
],{allowDiskUse:true})// 查找不在北京工作的员工（数组操作）
db.Employee.aggregate([
{"$match": {"Type" : "Office", "Addresses": {$not:{$elemMatch:{"Location": "Beijing"}}}}}
],{allowDiskUse:true})var result = db.Employee.distinct("No", {"Type" : "Office", "Location": "Beijing"})
db.Employee.aggregate([
{"$match": {"No": {$nin: result}}}
],{allowDiskUse:true})// 查找在北京工作，且有2个以上住宅的员工
db.Employee.aggregate([
{"$match": {"Type" : "Office", "Location": "Beijing"}},
{"$unwind": "$Addresses"},
{"$match": {"Addresses.Type": "House"}},
{"$group": {_id: "$No", "count": {"$sum": 1}}},
{"$match": {"count": {"$gt": 2}}},
{"sort": {"count":1}}
],{allowDiskUse:true})// 查找年龄为23-26，名字为Lily或Sam的员工
db.Employee.find({$or:[{"name":"Lily"},{"name":"Sam"}], "Age":{$gte: 23, $lte: 26}}, {"No":1, "Name":1, "_id":0})