updated: 2018/10/2
以下 mongo shell 上で
> db
// show databases
> use DB_NAME
// change current database
> db.testMongo.insertOne(
{
body: "test mongo operation",
id: 1
}
)
// create testMongo collection and insert a document
> show collections
// testMongo
データの削除
$d = db.COLLECTION_NAME.findOne()
db.COLLECTION_NAME.deleteOne($d)
document model structure
References Data Models (normalized data models)
→ RDBMS風にcollectionを分割してrelated_id でrelational に管理する場合
複雑な many to many relationships に対応できる
多階層のrelationships に対応できる
可読性が下がる
処理を実現するための query が長くなる
Embedded Data Models (denormalized data models)
→ embed related data in a single structure or document.
RDBMS では複数にまたがっていたデータが単一の record で管理できるため、query が単純になる
可読性が高い
normalized data models よりデータの duplication が多いのでデータが大きくなる
参考：
Data Modeling Introduction — MongoDB Manual 3.6
Data Model Design — MongoDB Manual 3.6
lecture 55
Schema Validation
事前に collection に挿入する data に制限をかける
db.createCollection("students", { validator: { $jsonSchema: { bsonType: "object", required: [ "name", "year", "major", "gpa" ], properties: { name: { bsonType: "string", description: "must be a string and is required" }, gender: { bsonType: "string", description: "must be a string and is not required" }, year: { bsonType: "int", minimum: 2017, maximum: 3017, exclusiveMaximum: false, description: "must be an integer in [ 2017, 3017 ] and is required" }, major: { enum: [ "Math", "English", "Computer Science", "History", null ], description: "can only be one of the enum values and is required" }, gpa: { bsonType: [ "double" ], minimum: 0, description: "must be a double and is required" } } } } })
参考：
Schema Validation — MongoDB Manual 3.6
collection 作成後、設定した validation を確認する方法は…
> db.getCollectionInfos()
Data Type
BSON Types — MongoDB Manual 3.6
