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GNOME Data Access 3.0 manual | ![]() |
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Returns a GdaDataModel 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 13. Standard Schema and supported parameters
Object type | GDA identifier | Supported Parameters | Returned fields |
---|---|---|---|
Databases | GDA_CONNECTION_SCHEMA_DATABASES |
name | |
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, comma separated extra attributes (AUTO_INCREMENT) |
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, comma separated) 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, synonyms (comma separated) |
Tables' constraints | GDA_CONNECTION_SCHEMA_CONSTRAINTS |
"name" (name of table) | constraint name, constraint type (FOREIGN_KEY, PRIMARY_KEY, UNIQUE, CHECK), on fields (comma separated), definition, options (ON_UPDATE_*, ON_DELETE_*, DEFERRABLE, INITIALLY_DEFERRED) |