Schema Class Reference

Representation of an extension schema. More...

#include <schema.h>

Public Member Functions
	Schema (const std::string &name, const std::string &service, int version, const std::string &definition)
	Schema (sqlite3 *db, const rapidjson::Document &doc)
	Constructor for a schema. More...
int	getVersion ()
std::string	getService ()
bool	upgrade (sqlite3 *db, const rapidjson::Document &doc, const std::string &definition)
	Upgrade an existing schema. More...
bool	attach (sqlite3 *db)
	Attach the schema to the database handle if not already attached. More...

Detailed Description

Representation of an extension schema.

Each active schema has an instance of the class that is managed by the SchemaManager class. This is either created when Fledge restarts and reads the schema definition from the database or when a service requests an extension schema to be created.

The class is responsible for the creation and update of the extension schemas. The name, service, version and definition of each schema is written to a control table in the Fledge schema to allow for the versions to be tracked and also to allow the extension schemas to be attached.

Constructor & Destructor Documentation

Schema()

Schema::Schema	(	sqlite3 *	db,
		const rapidjson::Document &	doc
	)

Constructor for a schema.

This is the case when a service has requested a schema that does not already exist. We must create a new schema from scratch.

Parameters

db	SQLite3 database handle
doc	JSON definition of the schema to create

Member Function Documentation

attach()

bool Schema::attach

(

sqlite3 *

db

)

Attach the schema to the database handle if not already attached.

Parameters

db	The database handle to attach the schema to

Returns

bool True if the schema was attached

upgrade()

bool Schema::upgrade	(	sqlite3 *	db,
		const rapidjson::Document &	doc,
		const std::string &	definition
	)

Upgrade an existing schema.

The upgrade process is limited and will only do the following operations; add a new table, drop a table, add a new column to a table, drop a column from a table, add a new index or drop an index.

Parameters

db	The SQLite3 database connection
doc	The pre-parsed version of the schema definition
definition	The schema defintion for the new version of the schema as JSON
bool	True if the upgrade suceeded.

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The documentation for this class was generated from the following files:

• C/plugins/storage/sqlite/schema/include/schema.h
• C/plugins/storage/sqlite/schema/schema.cpp