|GNOME Data Access manual|
The GdaServerProvider(3) is the class you should implement for adding a new provider. This class is just a typical GObject-based class, with a set of virtual methods, that are the ones that you must implement. These virtual methods are declared in the class structure, in the gda-server-provider.h file. They are explained in detail in the following subsections.
Sets up the connection to the database back-end using the parameters received as arguments and returns a boolean TRUE if the connection is successfully established, otherwise FALSE.
Frees the resources allocated for the connection and returns TRUE if everything is ok
Executes a command and returns a GList of GdaDataModel(3) with the results.
Tests if a given feature is supported by the provider and the DB back-end. You can view the list of features in gda-connection.h, enumeration GdaConnectionFeature.
Returns a GdaDataModel(3) with the schema information requested. You can view the list of features in gda-connection.h, enumeration GdaConnectionSchema. This schema information is what describes the objects in the database, and is the way applications can manage the structure of several database systems without knowing anything about their specific way of retrieving this information.
The get_schema virtual method gets a GdaConnectionSchema argument, which describes the kind of schema the client making the call is interested in, along with a GdaParameterList argument, which contains the list of arguments sent by the user to explicitly provide more information for the search.
The information to be returned for each schema, along with the supported parameters, is described in the following table.
Table 1. Standard Schema and supported parameters
|Object type||GDA identifier||Supported Parameters||Returned fields|
|Schemas (also namespaces), a feature supported by Postgres which allows to define multiple domains within a single database||GDA_CONNECTION_SCHEMA_NAMESPACES||name|
|Tables||GDA_CONNECTION_SCHEMA_TABLES||"name" (name of table, optional)||name, owner, comments, SQL definition|
|Tables' parents||GDA_CONNECTION_SCHEMA_PARENT_TABLES||"name" (name of table, optional)||name, order of inheritance|
|Views||GDA_CONNECTION_SCHEMA_VIEWS||"name" (name of view, optional)||name, owner, comments, SQL definition|
|Table (or view) fields||GDA_CONNECTION_SCHEMA_FIELDS||"name" (name of table (or view), required)||name, type, size, scale, not null?, primary key?, unique index?, references, default value|
|Sequences||GDA_CONNECTION_SCHEMA_SEQUENCES||"name" (name of sequence, optional)||name, owner, comments, SQL definition|
|Procedures||GDA_CONNECTION_SCHEMA_PROCEDURES||"name" (name of procedure, optional)||name, unique id, owner, comments, return type, number of arguments, arguments types (arguments types in the order, separated by spaces) and SQL definition. For the arguments where any type is accepted, '-' is returned as type.|
|Aggregates||GDA_CONNECTION_SCHEMA_AGGREGATES||"name" (name of aggregate, optional)||name, unique id, owner, comments, return type, argument type, SQL definition. If the argument can be of any type, then '-' is returned as type.|
|Types||GDA_CONNECTION_SCHEMA_TYPES||"name" (name of type, optional)||name, owner, comments, GDA type|
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