Re: [gnome-db] Getting table schemea fields in libgda 0.8.105

[Rodrigo Moya <rodrigo gnome-db org>]

On Tue, 2002-03-19 at 12:28, Daniel Morgan wrote:
> Is the function gda_recordset_describe_column supposed to be private and
> not to be seen by a gda client program?
> 
yes, it's private, because it is the implementation of the virtual
method defined in its base class, GdaDataModel. So, to access that
function, you just have to call gda_data_model_describe_column for a
GdaRecordset.

> Since we are using data models, I thought I would try using
> gda_connect_get_schema.
> 
> I tried writing a function to get the table schema, but it does not
> work.  What is the best way for a client application to get meta data
> about table columns? column name, defined size, scale, nullable?
> 
with the GDA_CONNECTION_SCHEMA_FIELDS, but there is some f***g bug lying
around which I could not find last night. It is somewhere in the
GdaParameter's management.

> Below, I have provided the source to my function to get the table schema
> and return it as a GdaDataModel.
> 
> GdaDataModel* get_table_schema(GdaConnection *cnc, gchar *table_name)
> {
> 	GdaParameterList * parm_list;
> 	GdaParameter * parm;
> 	GdaDataModel * model;
> 	GdaValue * value;	
> 
> 	if(!cnc)
> 		return NULL;
> 	if(!table_name)
> 		return NULL;
> 
> 	parm_list = gda_parameter_list_new();
> 	parm = gda_parameter_new("name", GDA_VALUE_TYPE_STRING);
> 	value = gda_value_new_string(table_name);
> 	gda_parameter_set_value(parm, value);
> 
you can use instead:

	parm = gda_parameter_new_string ("name", table_name);

> 	gda_parameter_list_add_parameter(parm_list, parm);
> 
> 	model = gda_connection_get_schema (cnc, 
> 			GDA_CONNECTION_SCHEMA_FIELDS, parm_list);
> 	
> 	gda_value_free(value);
> 	gda_parameter_free(parm);
> 	gda_parameter_list_free(parm_list);
> 
> 	return model;
> }
> 
your code looks ok. As I said, the problem is in the parameter
management.

cheers
-- 
Rodrigo Moya <rodrigo gnome-db org> - <rodrigo ximian com>
http://www.gnome-db.org/ - http://www.ximian.com/