Exemple #1
0
/*!
  \brief Open database (OGR datasource)

  \param handle pointer to dbHandle (db name and schema)

  \return DB_OK on success
  \return DB_FAILED on failure
*/
int db__driver_open_database(dbHandle * handle)
{
    const char *name;
    dbConnection connection;

    init_error();
    db_get_connection(&connection);
    name = db_get_handle_dbname(handle);

    /* if name is empty use connection.databaseName */
    if (strlen(name) == 0)
	name = connection.databaseName;

    G_debug(3, "db_driver_open_database() name = '%s'", name);

    OGRRegisterAll();

    hDs = OGROpen(name, TRUE, NULL);

    if (hDs == NULL) {
	append_error(_("Unable to open OGR data source"));
	report_error();
	return DB_FAILED;
    }

    G_debug(3, "Datasource opened");

    return DB_OK;
}
Exemple #2
0
/*!
  \brief Sets up database connection settings using GRASS default from dbmi.h

  \todo DB_OK on success, DB_* error code on fail

  \return returns DB_OK 
*/
int db_set_default_connection(void)
{
    dbConnection connection;
    char buf[GPATH_MAX];

    G_debug(1,
	    "Creating new default DB params with db_set_default_connection()");

    /* is this really needed ? */
    db_get_connection(&connection);

    if (strcmp(DB_DEFAULT_DRIVER, "dbf") == 0) {
	/* Set default values and create dbf db dir */

	connection.driverName = "dbf";
	connection.databaseName = "$GISDBASE/$LOCATION_NAME/$MAPSET/dbf/";
	db_set_connection(&connection);

	sprintf(buf, "%s/%s/dbf", G_location_path(), G_mapset());
	G__make_mapset_element("dbf");
    }
    else if (strcmp(DB_DEFAULT_DRIVER, "sqlite") == 0) {
	/* Set default values and create dbf db dir */

	connection.driverName = "sqlite";
	/*
	 * TODO: Use one DB for entire mapset (LFS problems?)
	 *      or per-map DBs in $MASPET/vector/mapname/sqlite.db (how to set that here?)
	 *      or $MAPSET/sqlite/mapname.sql as with dbf?
	 */
	connection.databaseName =
	    "$GISDBASE/$LOCATION_NAME/$MAPSET/sqlite.db";
	db_set_connection(&connection);
    }
    else
	G_fatal_error(_("Programmer error"));

    return DB_OK;
}
Exemple #3
0
Fichier : db.c Projet : caomw/grass
int db__driver_open_database(dbHandle * handle)
{
    char buf[500];
    const char *name, *schema, *user, *password;
    dbConnection connection;
    PGCONN pgconn;
    PGresult *res;
    int row;

    db_get_connection(&connection);
    name = db_get_handle_dbname(handle);

    /* if name is empty use connection.databaseName */
    if (strlen(name) == 0)
	name = connection.databaseName;

    G_debug(3,
	    "db_driver_open_database(): driver=pg database definition = '%s'",
	    name);

    if (parse_conn(name, &pgconn) == DB_FAILED) {
	db_d_report_error();
	return DB_FAILED;
    }

    G_debug(3,
	    "db_driver_open_database(): host = %s, port = %s, options = %s, tty = %s, "
	    "dbname = %s, user = %s, password = %s, "
	    "schema = %s", pgconn.host, pgconn.port, pgconn.options,
	    pgconn.tty, pgconn.dbname, pgconn.user, pgconn.password,
	    pgconn.schema);

    db_get_login("pg", name, &user, &password);

    pg_conn = PQsetdbLogin(pgconn.host, pgconn.port, pgconn.options, pgconn.tty,
			   pgconn.dbname, user, password);
    
    if (PQstatus(pg_conn) == CONNECTION_BAD) {
	db_d_append_error("%s\n%s",
			  _("Connection failed."),
			  PQerrorMessage(pg_conn));
	db_d_report_error();
	PQfinish(pg_conn);
	return DB_FAILED;
    }

    /* set schema */
    schema = db_get_handle_dbschema(handle);

    /* Cannot use default schema because link to table can point to
       different database */
    /*
       if ( schema ) 
       schema = connection.schemaName;
    */

    if (pgconn.schema) {
	schema = pgconn.schema;
    }

    /* set path to the schema */
    if (schema && strlen(schema) > 0) {
	sprintf(buf, "set search_path to %s", schema);
	res = PQexec(pg_conn, buf);

	if (!res || PQresultStatus(res) != PGRES_COMMAND_OK) {
	    db_d_append_error("%s %s",
			      _("Unable to set schema:"),
			      schema);
	    db_d_report_error();
	    PQclear(res);
	    return DB_FAILED;
	}
    }

    /* read internal codes */
    res = PQexec(pg_conn,
		 "select oid, typname from pg_type where typname in ( "
		 "'bit', 'int2', 'int4', 'int8', 'serial', 'oid', "
		 "'float4', 'float8', 'numeric', "
		 "'char', 'bpchar', 'varchar', 'text', "
		 "'time', 'date', 'timestamp', "
		 "'bool', 'geometry', 'topogeometry') order by oid");
    
    if (!res || PQresultStatus(res) != PGRES_TUPLES_OK) {
	db_d_append_error(_("Unable to select data types"));
	db_d_report_error();
	PQclear(res);
	return DB_FAILED;
    }

    pg_ntypes = PQntuples(res);
    pg_types = G_realloc(pg_types, 2 * pg_ntypes * sizeof(int));

    for (row = 0; row < pg_ntypes; row++) {
	int pgtype, type;

	pgtype = atoi(PQgetvalue(res, row, 0));

	pg_types[row][0] = pgtype;

        G_debug(3, "row = %d value = %s", row, PQgetvalue(res, row, 1));
	if (strcmp(PQgetvalue(res, row, 1), "bit") == 0)
	    type = PG_TYPE_BIT;
	else if (strcmp(PQgetvalue(res, row, 1), "int2") == 0)
	    type = PG_TYPE_INT2;
	else if (strcmp(PQgetvalue(res, row, 1), "int4") == 0)
	    type = PG_TYPE_INT4;
	else if (strcmp(PQgetvalue(res, row, 1), "int8") == 0)
	    type = PG_TYPE_INT8;
	else if (strcmp(PQgetvalue(res, row, 1), "serial") == 0)
	    type = PG_TYPE_SERIAL;
	else if (strcmp(PQgetvalue(res, row, 1), "oid") == 0)
	    type = PG_TYPE_OID;
	else if (strcmp(PQgetvalue(res, row, 1), "float4") == 0)
	    type = PG_TYPE_FLOAT4;
	else if (strcmp(PQgetvalue(res, row, 1), "float8") == 0)
	    type = PG_TYPE_FLOAT8;
	else if (strcmp(PQgetvalue(res, row, 1), "numeric") == 0)
	    type = PG_TYPE_NUMERIC;
	else if (strcmp(PQgetvalue(res, row, 1), "char") == 0)
	    type = PG_TYPE_CHAR;
	else if (strcmp(PQgetvalue(res, row, 1), "bpchar") == 0)
	    type = PG_TYPE_BPCHAR;
	else if (strcmp(PQgetvalue(res, row, 1), "varchar") == 0)
	    type = PG_TYPE_VARCHAR;
	else if (strcmp(PQgetvalue(res, row, 1), "text") == 0)
	    type = PG_TYPE_TEXT;
	else if (strcmp(PQgetvalue(res, row, 1), "date") == 0)
	    type = PG_TYPE_DATE;
	else if (strcmp(PQgetvalue(res, row, 1), "time") == 0)
	    type = PG_TYPE_TIME;
	else if (strcmp(PQgetvalue(res, row, 1), "timestamp") == 0)
	    type = PG_TYPE_TIMESTAMP;
	else if (strcmp(PQgetvalue(res, row, 1), "bool") == 0)
	    type = PG_TYPE_BOOL;
	else if (strcmp(PQgetvalue(res, row, 1), "geometry") == 0)
	    type = PG_TYPE_POSTGIS_GEOM;
	else if (strcmp(PQgetvalue(res, row, 1), "topogeometry") == 0)
	    type = PG_TYPE_POSTGIS_TOPOGEOM;
	else
	    type = PG_TYPE_UNKNOWN;

	G_debug(3, "db_driver_open_database(): pgtype = %d, name = %s -> type = %d", pgtype,
		PQgetvalue(res, row, 1), type);
	pg_types[row][1] = type;
    }
    
    /* print notice messages only on verbose level */
    PQsetNoticeProcessor(pg_conn, notice_processor, NULL);
    
    PQclear(res);

    return DB_OK;
}
Exemple #4
0
int db__driver_open_database(dbHandle * handle)
{
    const char *name;
    int len;
    dbConnection connection;
    char buf[1024];
    DIR *dir;
    struct dirent *ent;
    char **tokens;
    int no_tokens, n;

    G_debug(2, "DBF: db__driver_open_database() name = '%s'",
	    db_get_handle_dbname(handle));

    db.name[0] = '\0';
    db.tables = NULL;
    db.atables = 0;
    db.ntables = 0;

    db_get_connection(&connection);
    name = db_get_handle_dbname(handle);

    /* if name is empty use connection.databaseName */
    if (strlen(name) == 0) {
	name = connection.databaseName;
    }

    strcpy(db.name, name);

    /* open database dir and read table ( *.dbf files ) names 
     * to structure */

    /* parse variables in db.name if present */
    if (db.name[0] == '$') {
	tokens = G_tokenize(db.name, "/");
	no_tokens = G_number_of_tokens(tokens);
	db.name[0] = '\0';	/* re-init */

	for (n = 0; n < no_tokens; n++) {
	    G_debug(3, "tokens[%d] = %s", n, tokens[n]);
	    if (tokens[n][0] == '$') {
		G_strchg(tokens[n], '$', ' ');
		G_chop(tokens[n]);
		strcat(db.name, G__getenv(tokens[n]));
		G_debug(3, "   -> %s", G__getenv(tokens[n]));
	    }
	    else
		strcat(db.name, tokens[n]);

	    strcat(db.name, "/");
	}
	G_free_tokens(tokens);
    }

    G_debug(2, "db.name = %s", db.name);

    errno = 0;
    dir = opendir(db.name);
    if (dir == NULL) {
	if (errno == ENOENT) {
	    int status;

	    status = G_mkdir(db.name);
	    if (status != 0) {	/* mkdir failed */
		append_error("Cannot create dbf database: %s\n", name);
		report_error();
		return DB_FAILED;
	    }
	}
	else {			/* some other problem */
	    append_error("Cannot open dbf database: %s\n", name);
	    report_error();
	    return DB_FAILED;
	}
    }

    while ((ent = readdir(dir))) {
	len = strlen(ent->d_name) - 4;
	if ((len > 0) && (G_strcasecmp(ent->d_name + len, ".dbf") == 0)) {
	    strcpy(buf, ent->d_name);
	    buf[len] = '\0';
	    add_table(buf, ent->d_name);
	}
    }

    closedir(dir);
    return DB_OK;
}
Exemple #5
0
int db__driver_open_database(dbHandle * handle)
{
    char *name;
    dbConnection default_connection;
    MYSQL *res;

    db_get_connection(&default_connection);
    name = G_store(db_get_handle_dbname(handle));

    /* if name is empty use default_connection.databaseName */
    if (strlen(name) == 0)
	name = default_connection.databaseName;

    G_debug(3, "db_driver_open_database() mysql: database definition = '%s'",
	    name);

    /* Embedded version */
    {
	char *datadir, *database;
	char *server_args[4];
	char *buf;

	if (!replace_variables(name, &datadir, &database)) {
	    db_d_append_error(_("Unable parse MySQL embedded database name"));
	    db_d_append_error(mysql_error(connection));
	    db_d_report_error();
	    return DB_FAILED;
	}

	server_args[0] = "mesql";	/* this string is not used */
	G_asprintf(&buf, "--datadir=%s", datadir);
	server_args[1] = buf;
	/* With InnoDB it is very slow to close the database */
	server_args[2] = "--skip-innodb";	/* OK? */
	/* Without --bootstrap it complains about missing 
	 * mysql.time_zone_leap_second table */
	server_args[3] = "--bootstrap";	/* OK? */

	if (mysql_server_init(4, server_args, NULL)) {
	    db_d_append_error(_("Cannot initialize MySQL embedded server"));
	    db_d_append_error(mysql_error(connection));
	    db_d_report_error();
	    free(datadir);
	    free(database);
	    return DB_FAILED;
	}

	connection = mysql_init(NULL);
	mysql_options(connection, MYSQL_OPT_USE_EMBEDDED_CONNECTION, NULL);

	res =
	    mysql_real_connect(connection, NULL, NULL, NULL, database, 0,
			       NULL, 0);

	free(datadir);
	free(database);

	if (res == NULL) {
	    db_d_append_error(_("Unable to connect to MySQL embedded server: "));
	    db_d_append_error(mysql_error(connection));
	    db_d_report_error();
	    return DB_FAILED;
	}
    }

    return DB_OK;
}
Exemple #6
0
/*!
  \brief Get default information about link to database for new dblink
  
  \param Map pointer to Map_info structure
  \param field layer number
  \param field_name layer name
  \param type how many tables are linked to map: GV_1TABLE / GV_MTABLE 

  \return pointer to allocated field_info structure
 */
struct field_info *Vect_default_field_info(struct Map_info *Map,
					   int field, const char *field_name, int type)
{
    struct field_info *fi;
    char buf[GNAME_MAX], buf2[GNAME_MAX];
    const char *schema;
    dbConnection connection;

    G_debug(1, "Vect_default_field_info(): map = %s field = %d", Map->name,
	    field);
    
    if (Map->format == GV_FORMAT_OGR_DIRECT) {
	G_zero(&connection, sizeof(dbConnection));
	connection.driverName = G_store("ogr");
	connection.databaseName = G_store(Map->fInfo.ogr.dsn);
    }
    else {
	db_get_connection(&connection);
    }
    
    G_debug(2, "drv = %s db = %s", connection.driverName, connection.databaseName);
    
    if (!connection.driverName && !connection.databaseName) {
	/* Set default values */
	db_set_default_connection();
	db_get_connection(&connection);

	G_important_message(_("Default driver / database set to:\n"
			      "driver: %s\ndatabase: %s"), connection.driverName,
			    connection.databaseName);
    }
    /* they must be a matched pair, so if one is set but not the other
       then give up and let the user figure it out */
    else if (!connection.driverName) {
	G_fatal_error(_("Default driver is not set"));
    }
    else if (!connection.databaseName) {
	G_fatal_error(_("Default database is not set"));
    }

    fi = (struct field_info *)G_malloc(sizeof(struct field_info));

    fi->number = field;

    /* Table name */
    if (type == GV_1TABLE) {
	sprintf(buf, "%s", Map->name);
    }
    else {
	if (field_name != NULL && strlen(field_name) > 0)
	    sprintf(buf, "%s_%s", Map->name, field_name);
	else
	    sprintf(buf, "%s_%d", Map->name, field);
    }
    schema = connection.schemaName;
    if (schema && strlen(schema) > 0) {
	sprintf(buf2, "%s.%s", schema, buf);
	fi->table = G_store(buf2);
    }
    else {
	fi->table = G_store(buf);
    }

    /* Field name */
    if (field_name)
	fi->name = G_store(field_name);
    else
	fi->name = G_store(buf);

    fi->key = G_store(GV_KEY_COLUMN);	/* Should be: id/fid/gfid/... ? */
    fi->database = G_store(connection.databaseName);
    fi->driver = G_store(connection.driverName);

    return fi;
}
Exemple #7
0
int db__driver_create_table(dbTable * table)
{
    int col, ncols;
    dbColumn *column;
    const char *colname;
    int sqltype;
    char buf[500];
    PGresult *res;
    dbString sql;
    dbConnection connection;

    G_debug(3, "db__driver_create_table()");

    init_error();

    db_init_string(&sql);

    /* db_table_to_sql ( table, &sql ); */

    db_set_string(&sql, "create table ");
    db_append_string(&sql, db_get_table_name(table));
    db_append_string(&sql, " ( ");

    ncols = db_get_table_number_of_columns(table);

    for (col = 0; col < ncols; col++) {
	column = db_get_table_column(table, col);
	colname = db_get_column_name(column);
	sqltype = db_get_column_sqltype(column);

	G_debug(3, "%s (%s)", colname, db_sqltype_name(sqltype));

	if (col > 0)
	    db_append_string(&sql, ", ");
	db_append_string(&sql, colname);
	db_append_string(&sql, " ");
	switch (sqltype) {
	case DB_SQL_TYPE_CHARACTER:
	    sprintf(buf, "varchar(%d)", db_get_column_length(column));
	    db_append_string(&sql, buf);
	    break;
	case DB_SQL_TYPE_TEXT:
	    db_append_string(&sql, "text");
	    break;

	case DB_SQL_TYPE_SMALLINT:
	    db_append_string(&sql, "smallint");
	    break;
	case DB_SQL_TYPE_INTEGER:
	    db_append_string(&sql, "integer");
	    break;

	case DB_SQL_TYPE_REAL:
	    db_append_string(&sql, "real");
	    break;

	    /* TODO: better numeric types */
	case DB_SQL_TYPE_DOUBLE_PRECISION:
	case DB_SQL_TYPE_DECIMAL:
	case DB_SQL_TYPE_NUMERIC:
	case DB_SQL_TYPE_INTERVAL:
	    db_append_string(&sql, "double precision");
	    break;

	case DB_SQL_TYPE_DATE:
	    db_append_string(&sql, "date");
	    break;
	case DB_SQL_TYPE_TIME:
	    db_append_string(&sql, "time");
	    break;
	case DB_SQL_TYPE_TIMESTAMP:
	    db_append_string(&sql, "timestamp");
	    break;

	default:
	    G_warning("Unknown column type (%s)", colname);
	    return DB_FAILED;
	}
    }
    db_append_string(&sql, " )");


    G_debug(3, " SQL: %s", db_get_string(&sql));

    res = PQexec(pg_conn, db_get_string(&sql));

    if (!res || PQresultStatus(res) != PGRES_COMMAND_OK) {
	append_error("Cannot create table:\n");
	append_error(db_get_string(&sql));
	append_error("\n");
	append_error(PQerrorMessage(pg_conn));
	report_error();
	PQclear(res);
	db_free_string(&sql);
	return DB_FAILED;
    }

    PQclear(res);

    /* Grant privileges */
    db_get_connection(&connection);

    db_set_string(&sql, "grant select on ");
    db_append_string(&sql, db_get_table_name(table));
    db_append_string(&sql, " to public");

    if (connection.group) {
	db_append_string(&sql, ", group ");
	db_append_string(&sql, connection.group);
    }

    G_debug(3, " SQL: %s", db_get_string(&sql));

    res = PQexec(pg_conn, db_get_string(&sql));

    if (!res || PQresultStatus(res) != PGRES_COMMAND_OK) {
	append_error("Cannot grant select on table:\n");
	append_error(db_get_string(&sql));
	append_error("\n");
	append_error(PQerrorMessage(pg_conn));
	report_error();
	PQclear(res);
	db_free_string(&sql);
	return DB_FAILED;
    }

    PQclear(res);
    db_free_string(&sql);

    return DB_OK;
}
Exemple #8
0
/*!
  \brief Initialize a new dbDriver for db transaction.
 
  If <i>name</i> is NULL, the db name will be assigned 
  connection.driverName.
  
  \param name driver name
  
  \return pointer to dbDriver structure
  \return NULL on error
*/
dbDriver *db_start_driver(const char *name)
{
    dbDriver *driver;
    dbDbmscap *list, *cur;
    const char *startup;
    int p1[2], p2[2];
    int pid;
    int stat;
    dbConnection connection;
    char ebuf[5];

    /* Set some environment variables which are later read by driver.
     * This is necessary when application is running without GISRC file and all
     * gis variables are set by application. 
     * Even if GISRC is set, application may change some variables during runtime,
     * if for example reads data from different gdatabase, location or mapset*/

    /* setenv() is not portable, putenv() is POSIX, putenv() in glibc 2.0-2.1.1 doesn't conform to SUSv2,
     * G_putenv() as well, but that is what we want, makes a copy of string */
    if (G_get_gisrc_mode() == G_GISRC_MODE_MEMORY) {
	G_debug(3, "G_GISRC_MODE_MEMORY\n");
	sprintf(ebuf, "%d", G_GISRC_MODE_MEMORY);
	G_putenv("GRASS_DB_DRIVER_GISRC_MODE", ebuf);	/* to tell driver that it must read variables */

	if (G_getenv_nofatal("DEBUG")) {
	    G_putenv("DEBUG", G_getenv_nofatal("DEBUG"));
	}
	else {
	    G_putenv("DEBUG", "0");
	}

	G_putenv("GISDBASE", G_getenv_nofatal("GISDBASE"));
	G_putenv("LOCATION_NAME", G_getenv_nofatal("LOCATION_NAME"));
	G_putenv("MAPSET", G_getenv_nofatal("MAPSET"));
    }
    else {
	/* Warning: GISRC_MODE_MEMORY _must_ be set to G_GISRC_MODE_FILE, because the module can be 
	 *          run from an application which previously set environment variable to G_GISRC_MODE_MEMORY */
	sprintf(ebuf, "%d", G_GISRC_MODE_FILE);
	G_putenv("GRASS_DB_DRIVER_GISRC_MODE", ebuf);
    }

    /* read the dbmscap file */
    if (NULL == (list = db_read_dbmscap()))
	return (dbDriver *) NULL;

    /* if name is empty use connection.driverName, added by RB 4/2000 */
    if (name == '\0') {
	db_get_connection(&connection);
	if (NULL == (name = connection.driverName))
	    return (dbDriver *) NULL;
    }

    /* find this system name */
    for (cur = list; cur; cur = cur->next)
	if (strcmp(cur->driverName, name) == 0)
	    break;
    if (cur == NULL) {
	char msg[256];

	db_free_dbmscap(list);
	sprintf(msg, "%s: no such driver available", name);
	db_error(msg);
	return (dbDriver *) NULL;
    }

    /* allocate a driver structure */
    driver = (dbDriver *) db_malloc(sizeof(dbDriver));
    if (driver == NULL) {
	db_free_dbmscap(list);
	return (dbDriver *) NULL;
    }

    /* copy the relevant info from the dbmscap entry into the driver structure */
    db_copy_dbmscap_entry(&driver->dbmscap, cur);
    startup = driver->dbmscap.startup;

    /* free the dbmscap list */
    db_free_dbmscap(list);

    /* run the driver as a child process and create pipes to its stdin, stdout */

#ifdef __MINGW32__
#define pipe(fds) _pipe(fds, 250000, _O_BINARY | _O_NOINHERIT)
#endif

    /* open the pipes */
    if ((pipe(p1) < 0) || (pipe(p2) < 0)) {
	db_syserror("can't open any pipes");
	return (dbDriver *) NULL;
    }

    close_on_exec(p1[READ]);
    close_on_exec(p1[WRITE]);
    close_on_exec(p2[READ]);
    close_on_exec(p2[WRITE]);

    pid = G_spawn_ex(startup,
		     SF_BACKGROUND,
		     SF_REDIRECT_DESCRIPTOR, 0, p1[READ],
		     SF_CLOSE_DESCRIPTOR, p1[WRITE],
		     SF_REDIRECT_DESCRIPTOR, 1, p2[WRITE],
		     SF_CLOSE_DESCRIPTOR, p2[READ],
		     startup, NULL);

    /* create a child */
    if (pid < 0) {
	db_syserror("can't create fork");
	return (dbDriver *) NULL;
    }

    close(p1[READ]);
    close(p2[WRITE]);

    /* record driver process id in driver struct */
    driver->pid = pid;

    /* convert pipes to FILE* */
    driver->send = fdopen(p1[WRITE], "wb");
    driver->recv = fdopen(p2[READ], "rb");

    /* most systems will have to use unbuffered io to get the send/recv to work */
#ifndef USE_BUFFERED_IO
    setbuf(driver->send, NULL);
    setbuf(driver->recv, NULL);
#endif

    db__set_protocol_fds(driver->send, driver->recv);
    if (db__recv_return_code(&stat) != DB_OK || stat != DB_OK)
	driver = NULL;

    return driver;
}
Exemple #9
0
int main(int argc, char *argv[])
{
    dbConnection conn;
    struct Flag *print, *check_set_default, *def;

    /*    struct Option *driver, *database, *user, *password, *keycol; */
    struct Option *driver, *database, *schema, *group;
    struct GModule *module;

    /* Initialize the GIS calls */
    G_gisinit(argv[0]);

    /* Set description */
    module = G_define_module();
    G_add_keyword(_("database"));
    G_add_keyword(_("attribute table"));
    G_add_keyword(_("connection settings"));
    module->description =
	_("Prints/sets general DB connection for current mapset.");

    print = G_define_flag();
    print->key = 'p';
    print->description = _("Print current connection parameters and exit");
    print->guisection = _("Print");

    check_set_default = G_define_flag();
    check_set_default->key = 'c';
    check_set_default->description =
	_("Check connection parameters, set if uninitialized, and exit");
    check_set_default->guisection = _("Set");
    
    def = G_define_flag();
    def->key = 'd';
    def->label = _("Set from default settings and exit");
    def->description = _("Overwrite current settings if initialized");
    def->guisection = _("Set");

    driver = G_define_standard_option(G_OPT_DB_DRIVER);
    driver->options = db_list_drivers();
    driver->answer = (char *) db_get_default_driver_name();
    driver->guisection = _("Set");

    database = G_define_standard_option(G_OPT_DB_DATABASE);
    database->answer = (char *) db_get_default_database_name();
    database->guisection = _("Set");

    schema = G_define_standard_option(G_OPT_DB_SCHEMA);
    schema->answer = (char *) db_get_default_schema_name();
    schema->guisection = _("Set");

    group = G_define_option();
    group->key = "group";
    group->type = TYPE_STRING;
    group->required = NO;
    group->multiple = NO;
    group->answer = (char*) db_get_default_group_name();
    group->description = _("Default group of database users to which "
			   "select privilege is granted");
    group->guisection = _("Set");

    /* commented due to new mechanism:
       user = G_define_option() ;
       user->key        = "user" ;
       user->type       = TYPE_STRING ;
       user->required   = NO  ;
       user->multiple   = NO ;
       user->description= "User:"******"password" ;
       password->type       = TYPE_STRING ;
       password->required   = NO  ;
       password->multiple   = NO ;
       password->description= "Password:"******"driver:%s\n",
		    conn.driverName ? conn.driverName : "");
	    fprintf(stdout, "database:%s\n",
		    conn.databaseName ? conn.databaseName : "");
	    fprintf(stdout, "schema:%s\n",
		    conn.schemaName ? conn.schemaName : "");
	    fprintf(stdout, "group:%s\n", conn.group ? conn.group : "");
	}
	else
	    G_fatal_error(_("Database connection not defined. "
			    "Run db.connect."));

	exit(EXIT_SUCCESS);
    }

    if (check_set_default->answer) {
	/* check connection and set to system-wide default in required */
	/*
	 * TODO: improve db_{get,set}_connection() to not return DB_OK on error
	 *       (thus currently there is no point in checking for that here)
	 */
	db_get_connection(&conn);

	if (!conn.driverName && !conn.databaseName) {

	    db_set_default_connection();
	    db_get_connection(&conn);

	    G_important_message(_("Default driver / database set to:\n"
				  "driver: %s\ndatabase: %s"), conn.driverName,
				conn.databaseName);
	}
	/* they must be a matched pair, so if one is set but not the other
	   then give up and let the user figure it out */
	else if (!conn.driverName) {
	    G_fatal_error(_("Default driver is not set"));
	}
	else if (!conn.databaseName) {
	    G_fatal_error(_("Default database is not set"));
	}

	/* connection either already existed or now exists */
	exit(EXIT_SUCCESS);
    }


    if (def->answer) {
	db_set_default_connection();
	db_get_connection(&conn);
	
	G_important_message(_("Default driver / database set to:\n"
			      "driver: %s\ndatabase: %s"), conn.driverName,
			    conn.databaseName);
	exit(EXIT_SUCCESS);
    }
    
    /* set connection */
    db_get_connection(&conn);	/* read current */

    if (driver->answer)
	conn.driverName = driver->answer;

    if (database->answer)
	conn.databaseName = database->answer;

    if (schema->answer)
	conn.schemaName = schema->answer;

    if (group->answer)
	conn.group = group->answer;

    db_set_connection(&conn);


    exit(EXIT_SUCCESS);
}