Tag - mapping

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2014-05-09

BREAKING CHANGE: TSQLRestServerStatic* classes are now renamed as TSQLRestStorage*

By AB4327-GANDI, 2014-05-09. Open Source › mORMot Framework

From the beginning, server-side storage tables which were not store in a SQLite3 database were implemented via some classes inheriting from TSQLRestServerStatic.
This TSQLRestServerStatic was inheriting from TSQLRestServer, which did not make much sense (but was made for laziness years ago, if I remember well).

Now, a new TSQLRestStorage class, directly inheriting from TSQLRest, is used for per-table storage.
This huge code refactoring results in a much cleaner design, and will enhance code maintainability.
Documentation has been updated to reflect the changes.

Note that this won't change anything when using the framework (but the new class names): it is an implementation detail, which had to be fixed.

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2014-05-07

MongoDB + mORMot benchmark

By AB4327-GANDI, 2014-05-07. Open Source › mORMot Framework

Here are some benchmark charts about MongoDB integration in mORMot's ORM.

MongoDB appears as a serious competitor to SQL databases, with the potential benefit of horizontal scaling and installation/administration ease - performance is very high, and its document-based storage fits perfectly with mORMot's advanced ORM features like Shared nothing architecture (or sharding).

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MongoDB + mORMot ORM = ODM

By AB4327-GANDI, 2014-05-07. Open Source › mORMot Framework

MongoDB (from "humongous") is a cross-platform document-oriented database system, and certainly the best known NoSQL database.
According to http://db-engines.com in April 2014, MongoDB is in 5th place of the most popular types of database management systems, and first place for NoSQL database management systems.
Our mORMot gives premium access to this database, featuring full NoSQL and Object-Document Mapping (ODM) abilities to the framework.

Integration is made at two levels:

  • Direct low-level access to the MongoDB server, in the SynMongoDB.pas unit;
  • Close integration with our ORM (which becomes defacto an ODM), in the mORMotMongoDB.pas unit.

MongoDB eschews the traditional table-based relational database structure in favor of JSON-like documents with dynamic schemas (MongoDB calls the format BSON), which matches perfectly mORMot's RESTful approach.

This second article will focus on integration of MongoDB with our ORM.

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Direct MongoDB database access

By AB4327-GANDI, 2014-05-07. Open Source › mORMot Framework

MongoDB (from "humongous") is a cross-platform document-oriented database system, and certainly the best known NoSQL database.
According to http://db-engines.com in April 2014, MongoDB is in 5th place of the most popular types of database management systems, and first place for NoSQL database management systems.
Our mORMot framework gives premium access to this database, featuring full NoSQL and Object-Document Mapping (ODM) abilities to the framework.

Integration is made at two levels:

  • Direct low-level access to the MongoDB server, in the SynMongoDB.pas unit;
  • Close integration with our ORM (which becomes defacto an ODM), in the mORMotMongoDB.pas unit.

MongoDB eschews the traditional table-based relational database structure in favor of JSON-like documents with dynamic schemas (MongoDB calls the format BSON), which matches perfectly mORMot's RESTful approach.

In this first article, we will detail direct low-level access to the MongoDB server, via the SynMongoDB.pas unit.

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2014-03-13

ORM mapping class fields to external table columns

By AB4327-GANDI, 2014-03-13. Open Source › mORMot Framework

When working with an ORM, you have mainly two possibilites:

  1. Start from scratch, i.e. write your classes and let the ORM creates all the database structure - it is also named "code-first";
  2. From an existing database, you define in your model how your classes map the existing database structure - this is "database-first".

We have just finalized ORM external table field mapping in mORMot, using e.g.
aModel.Props[aExternalClass].ExternalDB.MapField(..)
See this last commit.

So you can write e.g.

fProperties := TSQLDBSQLite3ConnectionProperties.Create(
  SQLITE_MEMORY_DATABASE_NAME,'','','');
VirtualTableExternalRegister(fExternalModel,
  TSQLRecordPeopleExt,fProperties,'PeopleExternal');
fExternalModel.Props[TSQLRecordPeopleExt].ExternalDB.
  MapField('ID','Key').
  MapField('YearOfDeath','YOD');

Then you use your TSQLRecordPeopleExt table as usual from Delphi code, with ID and YearOfDeath fields:

  • The "internal" TSQLRecord class will be stored within the PeopleExternal external table;
  • The "internal" TSQLRecord.ID field will be an external "Key: INTEGER" column;
  • The "internal" TSQLRecord.YearOfDeath field will be an external "YOD: BIGINT" column;
  • Other internal published properties will be mapped by default with the same name to external column.

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