Take you in-depth understanding of AGC cloud database

Business Introduction

Traditional mobile application development , Developers need to build every service from scratch , A lot of development work , High threshold . Developers are writing application logic , Data management also needs to be addressed 、 End cloud data synchronization and server deployment and maintenance .

Cloud DB It is a database product for end cloud collaboration , Provide collaborative management of end cloud data 、 Unified data model and rich data management API Interface and other capabilities . In ensuring the availability of data 、 reliability 、 Uniformity , And security , It can realize the seamless synchronization of data between the client and the cloud , And provide offline support for applications , To help developers quickly build the end cloud 、 Application of multi terminal collaboration . meanwhile ,Cloud DB As AppGallery Connect Part of the solution , by AppGallery Connect The platform builds MBaaS（Mobile Backend as a Service, Mobile backend as a service ） Ability . So that application developers can focus on the business of the application itself , Greatly improve the productivity of developers .

The main function

Cloud DB It is a database product for end cloud collaboration , Support data in the end cloud 、 Seamless synchronization between multiple terminals , And provide offline support for applications , To help you quickly build the end cloud 、 Application of multi terminal collaboration .

• Flexible synchronization mode

  Cloud DB Support cache and local data synchronization modes . In cache mode , End side data is a subset of cloud side data , If persistence is allowed , The results of the query will be automatically cached to the end side ; In local mode , Data is only stored locally , Do not synchronize with cloud side data .

• Powerful query ability

  Cloud DB Support rich predicate queries , It can contain multiple chain filter conditions , You can combine filtering with sorting or limiting the number of returned result set objects . In cache mode , You can specify to query data from cloud side storage or local storage ; In local mode , Query data directly from local storage .

• Real time updates

  Cloud DB In cache mode , You can listen to the data you need to pay attention to , And make use of Cloud DB Data synchronization function , Change the data in the end cloud 、 Real time update between multiple devices .

• Offline Support

  Cloud DB In cache mode , If you allow cache persistence , When the device is offline , Application queries on cloud databases will change to local queries by default . When the device is back online ,Cloud DB All locally written data will be automatically synchronized to the cloud database .

• Extensibility

  Cloud DB It provides the functions of Huawei cloud's powerful infrastructure , Automatic multi region data replication 、 Atomicity of batch operations 、 Consistency assurance and transaction support .

• Security

  Cloud DB Support the whole process encryption data management of the end cloud ,APP、 Triple authentication of users and services , Role based permission management, etc , Ensure data security in an all-round way .

working principle

Cloud DB It supports the collaborative management of end cloud data 、 Extensible Serverless Database products , Provide easy-to-use multi platform native SDK, Your Android application 、iOS application 、Web application 、 Fast applications and fast games can be achieved through SDK Directly access the cloud side database . meanwhile ,Cloud DB It also supports the adoption of Server SDK Directly manage cloud side data , Realize efficient management of cloud side data .

Cloud DB Adopt the data storage structure based on object model . Data is stored in different storage areas in the form of objects , Every object , Is a complete data record . Object types are used to define a collection of stored objects , Different object types correspond to different data structures . A storage area is an independent data storage area , Each store has exactly the same object type definition . You can AppGallery Connect Console , Define object types 、 Create storage and manage data .Cloud DB Support for multiple data type , Include simple strings 、 Values, text, etc .

Cloud DB It also provides multiple data security policies . Full process encryption management capability based on privacy or sensitive data , The data of the encrypted field will be encrypted on the end side , Then it is sent in ciphertext form and stored on the cloud side , Only application users can obtain key information and access their own encrypted data according to the password they enter . Role based Rights management Model , To ensure data security . By preset 4 Kind of characters and 3 Species jurisdiction , Simplify your rights management operations . You can AppGallery Connect The console can simply set unique permissions for each object type .

Platform support description

First level classification	Secondary classification	Whether... Is supported
client SDK	Android
	iOS
	Web
	Apply it quickly
	Play fast
Server SDK	Java
	JavaScript
Cross platform framework	Flutter
	React Native
	Cordova
	Xamarin
	lonic
Third party Library （ Implemented by a third party ）	Unity
	Cocos

Data model

Cloud DB Is a database based on object model , Adopt storage area 、 Object type and object three-level structure . When developing applications , Each application will instantiate one Cloud DB example , Based on this example , You can create multiple stores .

Storage area

Storage area （ namely Cloud DB zone） Is an independent data storage area , Multiple data stores are independent of each other . Each store has exactly the same object type definition , You can customize the objects stored in the storage area according to the needs of the application .

object type

object type （ namely ObjectType） Used to define a collection of storage objects , Different object types correspond to different data structures . Every time you create an object type ,Cloud DB An object type corresponding to its structure will be instantiated in each storage area , Used to store corresponding data .

object

object （ namely CloudDBZoneObject） yes Cloud DB The basic operating unit of , Every object , Is a complete data record .

data type

Cloud DB Support multiple data types , Such as surface 1 Shown , Describes the various data types supported and their sorting instructions .

surface 1  Data type table

data type	explain	Sort description
String	describe ： String type Value range ： Maximum length 200 explain If the string length exceeds 200, It is recommended to use Text type .	use UTF-8 Encoded byte order
Boolean	describe ： Boolean type Value range ： true： really false： false	false < true
Byte	describe ： Single byte integer Value range ：-128 ~ +127	Number order
Short	describe ： Double byte integer Value range ：-32,768 ~ +32,767
Integer	describe ： Four byte integer Value range ：-2,147,483,648 ~ +2,147,483,647
Long	describe ： Octet integer Value range ：-9,223,372,036,854,775,808 ~ 9,223,372,036,854,775,807
Float	describe ： Single-precision floating-point Value range ：-3.40E+38 ~ +3.40E+38,6 Decimal significant digits .
Double	describe ： Double precision floating point Value range ：-1.79E+308 ~ +1.79E+308,15 Decimal significant digits .
ByteArray	Byte array , Generally used for data storage of file types , Such as images 、 Documents and videos, etc . On the end side , Use Android When developing applications , With byte[] Expressed as a byte array .	use UTF-8 Encoded byte order
Text	Text type .
Date	The date type .	Time sequence

explain

because JavaScript Data type is not supported “Long”,Web SDK Support data types by introducing third-party open source components “Long” The ability of .“Long” For the usage of type, please refer to https://github.com/dcodeIO/long.js.

Rights management

Cloud DB It supports the authentication of all users' access , Ensure the security of application data . Cloud side access Cloud DB The default user role of is “ Administrators ” role , From AppGallery Connect Console 、 Cloud functions and Server End access Cloud DB Role , This role has all permissions by default . The end side is the application running end , The data operation on the end side is restricted by strict security rules , The data read / write permission is controlled according to the cloud side permission management table .

Cloud DB Support application development based on cache mode and local mode , In different modes , The authority management of data is also inconsistent .

• In cache mode , After the data synchronization channel is established on the end side and the cloud side , The end side will synchronize the permission management table on the cloud side to the end side , The end side will perform permission control on the data according to the permission management table .
• In local mode , The data operation on the end side is not affected by the permission management table on the cloud side , The end side has full operation authority for the data it contains .

explain

• In the cache mode, the following scenarios , The data operation authority of the end user is as follows ：

  • After the user installs the application , Before the end side application establishes a synchronization channel with the cloud side for the first time , The end user has no permission . After the end-side application obtains the permission management table from the cloud side , End user permissions are allocated according to the permission configuration table .
  • The end user is due to AppGallery Connect Failure of authentication information （ For example, the offline duration exceeds the effective time of the authentication information ） Or write off AppGallery Connect After certification , The role of the end user is defined by “ Authenticated user ” Turn into “ All the people ”, At this time, the end user has the same permissions as “ All the people ” The permissions of roles are consistent .

Cloud DB Defines everyone 、 Authenticated user 、 Data creators and administrators 4 Roles ,query、upsert（ Including addition and modification ） and delete 3 Species jurisdiction .

surface 1  Permission configuration table

role	query	upsert	delete
All the people	*	–	–
Authenticated user	*	*	√
Data creator	*	*	√
Administrators	*	*	*

• All the people ： On behalf of all users , Including authenticated and non authenticated users . By default, this role has query jurisdiction , Not configurable upsert and delete jurisdiction .
• Authenticated user ： after AppGallery Connect Login authenticated user . By default, this role has query jurisdiction , Customizable configuration upsert and delete jurisdiction .
• Data creator ： Authenticated data creation user , Each data has its corresponding data creator （ That is, the application user ）, Each data creator can only upsert perhaps delete Create your own data , You can't upsert perhaps delete Data created by others . The information of the data creator is saved in the system table of the data record . This role has all permissions by default , All permissions can be customized .
• Administrators ： Application Developer , Mainly means through AppGallery Connect Console or FaaS（Function as a Service, Functions are services ） Side access Cloud DB Role . This role has all permissions by default , All permissions can be customized . Administrators can manage and configure permissions for other roles .

explain

• When developing end-to-side applications , If you want to use the relevant permissions of the authenticated user , Need to open AppGallery Connect Certification services .
• When the encryption field is set in the object type , Indicates that the whole process encryption function is enabled , here “ All the people ” and “ Authenticated user ” The character will not have query、upsert and delete jurisdiction , And modification is not allowed .
• Authenticated users include anonymous authentication and formal registration , It is recommended that you use the full encryption function , This function is only available to officially registered users , It is not recommended to open the whole process encryption function to anonymous users . Because when using this function , The user needs to enter a password ,Cloud DB Will use this password to derive key information , And save the ciphertext of key information and encrypted user data ciphertext on the cloud side , The key information will be bound to the user account , Only the user can obtain the key information and access his own encrypted data according to the password . The account number of an anonymous user changes dynamically after each login , That is, each login is a new user , Even if the key information is stored on the cloud side , The key information saved on the cloud side cannot be used for the next login .

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