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GNOME Data Access 3.0 manual | ![]() |
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A single piece of data can have several representations depending on its usage: a string representation, an SQL representation and of course a GValue representation. Conversions from one representation to the other is DBMS dependant as each database can have its own SQL representation rules. The GdaDataHandler object's purpose is to do all these conversions in a easy way. Except when mentionned otherwise, conversions take into account locale settings and DBMS specifications.
To convert a data, one needs to instanciate a new data handler from one of the many classes which implement this interface, or better to get a pointer to a GdaDataHandler object (no need to unref() it after usage, data handler objects are stateless), and so to obtain such a pointer one can:
Ask a GdaDict object for one using the gda_dict_get_default_handler(): the returned data handler is a generic one and should not be used to convert data to use with any connection, but only to have a portable way of storing and loading data in a locale independant fashion (for serialization purposes).
Ask a GdaDict object for one using the gda_dict_get_handler(): the returned data handler can safely be used to convert data to use with the connection assigned to the dictionary (see this method's documentation for more information)
Ask a GdaServerProvider object for one using the gda_server_provider_get_data_handler_gtype() or gda_server_provider_get_data_handler_dbms(): the returned data handler can then safely be used to convert any data to be used with any connection relying on the GdaServerProvider object.