[gnome-db] Question about gda_column_get_table

[Juan Manuel Mouriz <jmouriz gmail com>]

Good night list. I write the following program using GDA, but I have a doubt about red painted code:

#include <gtk/gtk.h>
#include <libgda/libgda.h>
#include <stdio.h>

#define DSN "DB_DIR=.;DB_NAME=balance.db"

#define UNKNOWN_ERROR "No hay ningún detalle de este error"

typedef struct _Data {
  GtkTreeView *tree_view;
  gint position;
  const gchar *table;
  const gchar *name;
} Data;

/* Muestra un diálogo de error al usuario */
void
show_error_dialog (const gchar *title, const gchar *message, const gchar *error)
{
    GtkWidget *dialog;

    dialog = gtk_message_dialog_new_with_markup (NULL, 0, GTK_MESSAGE_ERROR, GTK_BUTTONS_CLOSE, 
      error ? "<span weight=\"heavy\" size=\"larger\">%s</span>" : "%s", message);

    if (error)
      gtk_message_dialog_format_secondary_markup (GTK_MESSAGE_DIALOG (dialog), "%s", error);

    gtk_window_set_title (GTK_WINDOW (dialog), title ? title : "Error");
    gdk_beep ();
    gtk_dialog_run (GTK_DIALOG (dialog));
    gtk_widget_destroy (dialog);
}

/* Función que se ejecuta cada vez que se edita una celda */
static void
cell_edited (GtkCellRendererText *renderer, const gchar *path, const gchar *value, gpointer data)
{
  GtkTreeModel *model = gtk_tree_view_get_model (GTK_TREE_VIEW (((Data *) data)->tree_view));
  gint column_number = ((Data *) data)->position;
  const gchar *table = ((Data *) data)->table;
  const gchar *name = ((Data *) data)->name;

  g_debug ("update %s set %s = '%s'\n", table, name, value);

  GtkTreeIter iter;

  gtk_tree_model_get_iter (model, &iter, gtk_tree_path_new_from_string (path));
  gtk_list_store_set (GTK_LIST_STORE (model), &iter, column_number, value, -1);
}

/* Exponer los datos en la vista */
void
expose_data_model (const gchar *table, GdaDataModel *data_model, GtkTreeView *tree_view)
{
  GList *columns = NULL;
  gint column_count = -1;

  GtkTreeViewColumn *column;
  GtkCellRenderer *renderer;
  GtkTreeModel *model;
  GType *types;
  gint column_number;
  gint row_count;
  gint row_number;
  GtkTreeIter iter;

  if ((row_count = gda_data_model_get_n_rows (data_model)) < 1)
    return;

  columns = gtk_tree_view_get_columns (tree_view);

  while (g_list_nth (columns, ++column_count))
    gtk_tree_view_remove_column (tree_view, g_list_nth_data (columns, column_count));

  g_list_free (columns);

  if ((column_count = gda_data_model_get_n_columns (data_model)) < 1)
    return;

  types = g_new0 (GType, column_count * 2);

  for (column_number = 0; column_number < column_count; column_number++) {
    const gchar *name = gda_data_model_get_column_name (data_model, column_number);

    GdaColumn *column_description = gda_data_model_describe_column (data_model, column_number);
    g_debug ("table: %s\n", gda_column_get_table (column_description));

    Data *data = "" (sizeof (Data));
    data->tree_view = tree_view;
    data->position = column_number;
    data->table = table;
    data->name = name;

    renderer = gtk_cell_renderer_text_new ();
    g_object_set (renderer, "editable", TRUE, NULL);
    g_signal_connect (renderer, "edited", G_CALLBACK (cell_edited), data);
    column = gtk_tree_view_column_new_with_attributes (name, renderer, "text", column_number, "xalign",
      column_count + column_number, NULL);
    gtk_tree_view_append_column (tree_view, column);
    types[column_number] = G_TYPE_STRING;
    types[column_count + column_number] = G_TYPE_FLOAT;
  }

  model = GTK_TREE_MODEL (gtk_list_store_newv (column_count * 2, types));
  gtk_tree_view_set_model (tree_view, model);

  for (row_number = 0; row_number < row_count; row_number++) {
    gtk_list_store_append (GTK_LIST_STORE (model), &iter);

    for (column_number = 0; column_number < column_count; column_number++) {
      const GValue *value = gda_data_model_get_value_at (data_model, column_number, row_number);

      gtk_list_store_set (GTK_LIST_STORE (model), &iter, column_number, gda_value_stringify (value), -1);

      if (!G_VALUE_HOLDS_STRING (value))
        gtk_list_store_set (GTK_LIST_STORE (model), &iter, column_count + column_number, 1.0, -1);
    }
  }
}

/* Función que se ejecuta cuando se cierra la ventana */
gboolean
window_delete_event (GtkWidget *widget, GdkEvent *event, gpointer data)  
{
  gtk_main_quit ();
}

/* Punto de entrada */
int
main (int argc, char *argv[])
{
  GdaConnection *connection;
  GtkWidget *window;
  GtkWidget *scrolled_window;
  GtkWidget *tree_view;
  GError *error;

  gtk_init (&argc, &argv);
  gda_init ();

  /* Crear la conexión a la base de datos */
  error = NULL;
  connection = gda_connection_open_from_string ("SQLite", DSN, NULL, 0, &error);

  if (!connection) {
    show_error_dialog ("Error de conexión", error && error->message ? error->message : UNKNOWN_ERROR, NULL);
    return (1);
  }

  /* Abrir la conexión */
  error = NULL;
  if (!gda_connection_open (connection, &error)) {
    show_error_dialog ("Error de conexión", error && error->message ? error->message : UNKNOWN_ERROR, NULL);
    return (1);
  }

  /* Actualizar el diccionario */
  error = NULL;
  if (!gda_connection_update_meta_store (connection, NULL, &error)) {
    show_error_dialog ("Error de conexión", error && error->message ? error->message : UNKNOWN_ERROR, NULL);
    return (1);
  }

  /* Definición de la GUI */
  window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
  scrolled_window = gtk_scrolled_window_new (NULL, NULL);
  tree_view = gtk_tree_view_new ();

  /* Cargar datos */
  GdaStatement *statement;
  GdaDataModel *data_model;
  GdaSqlParser *parser = gda_connection_create_parser (connection);

  if (!parser)
    parser = gda_sql_parser_new ();

  if (!parser) {
    show_error_dialog ("Error interno", "No se puede crear el analizador sintáctico para interpretar comandos SQL", NULL);
    return (1);
  }

  g_object_set_data_full (G_OBJECT (connection), "parser", parser, g_object_unref);

  error = NULL;
  statement = gda_sql_parser_parse_string (parser, "select obras.obra_id || ':' || complejos.complejo_id || ':' || unidades.unidad_id as id, "
    "obras.obra, complejos.complejo, unidades.unidad, unidades.cantidad from unidades inner join complejos on complejos.complejo_id = "
    "unidades.complejo_id inner join obras on obras.obra_id = complejos.obra_id order by 1", NULL, &error);

  if (!statement) {
    show_error_dialog ("Error SQL", error && error->message ? error->message : UNKNOWN_ERROR, NULL);
    return (1);
  }

  data_model = gda_data_model_query_new (connection, statement);
  g_object_unref (statement);

  if (!data_model) {
    show_error_dialog ("Error SQL", error && error->message ? error->message : UNKNOWN_ERROR, NULL);
    return (1);
  }

  expose_data_model ("materiales", data_model, GTK_TREE_VIEW (tree_view));

  gda_data_model_dump (data_model, stdout);

  /* Construir la GUI */
  gtk_container_add (GTK_CONTAINER (scrolled_window), tree_view);
  gtk_container_add (GTK_CONTAINER (window), scrolled_window);

  /* Conectar todas las señales */
  g_signal_connect (window, "delete_event", G_CALLBACK (window_delete_event), NULL);

  /* Comenzar la iteración con el usuario */
  gtk_widget_show_all (window);

  gtk_main ();

  return 0;
}

Why I don't get the table name? How to can I get this?

Thanks