Geografic-Information-System/db/drivers/dbf/describe.c

/*****************************************************************************
*
* MODULE:       DBF driver 
*   	    	
* AUTHOR(S):    Radim Blazek
*
* PURPOSE:      Simple driver for reading and writing dbf files     
*
* COPYRIGHT:    (C) 2000 by the GRASS Development Team
*
*               This program is free software under the GNU General Public
*   	    	License (>=v2). Read the file COPYING that comes with GRASS
*   	    	for details.
*
*****************************************************************************/

#include <grass/dbmi.h>
#include <grass/datetime.h>
#include <grass/shapefil.h>
#include <grass/glocale.h>
#include "globals.h"
#include "proto.h"

int db__driver_describe_table(dbString * table_name, dbTable ** table)
{
    int tab;
    char *name;

    name = db_get_string(table_name);

    tab = find_table(name);
    if (tab == -1) {
	db_d_append_error(_("Table '%s' doesn't exist"),
			  db_get_string(table_name));
	db_d_report_error();
	return DB_FAILED;
    }
    describe_table(tab, NULL, 0, table);

    return DB_OK;
}

/* scols is array of indexes selected columns or null,
 * if nscols == 0 => describe all columns */
int describe_table(int tab, int *scols, int nscols, dbTable ** table)
{
    int i, col, ncols, dbtype, precision, scale;
    dbColumn *column;
    COLUMN *dcol;

    load_table_head(tab);
    ncols = db.tables[tab].ncols;

    if (nscols > 0)
	ncols = nscols;

    if (!(*table = db_alloc_table(ncols))) {
	return DB_FAILED;
    }

    for (i = 0; i < ncols; i++) {
	if (nscols > 0)
	    col = scols[i];
	else
	    col = i;

	dcol = &(db.tables[tab].cols[col]);
	column = db_get_table_column(*table, i);

	db_set_column_name(column, dcol->name);
	db_set_column_length(column, dcol->width);
	db_set_column_host_type(column, dcol->type);

	switch (dcol->type) {
	case DBF_INT:
	    dbtype = DB_SQL_TYPE_INTEGER;
	    precision = dcol->width - 1;	/* one char for sign */
	    scale = 0;
	    break;
	case DBF_DOUBLE:
	    dbtype = DB_SQL_TYPE_DOUBLE_PRECISION;
	    precision = dcol->width - 2;	/* one char for sign second for decimal point */
	    scale = dcol->decimals;
	    break;
	case DBF_CHAR:
	    dbtype = DB_SQL_TYPE_CHARACTER;
	    precision = 0;
	    scale = 0;
	    break;

	default:
	    dbtype = DB_SQL_TYPE_UNKNOWN;
	    break;
	}

	db_set_column_sqltype(column, dbtype);

	/* precision is number of digits */
	db_set_column_precision(column, precision);
	/* scale is number of digits to the right of decimal point */
	db_set_column_scale(column, scale);

	db_set_column_null_allowed(column);
	db_set_column_has_undefined_default_value(column);
	db_unset_column_use_default_value(column);

	db_set_column_select_priv_granted(column);

	if (db.tables[tab].write)
	    db_set_column_update_priv_granted(column);
	else
	    db_set_column_update_priv_not_granted(column);


    }

    /* set the table name */
    db_set_table_name(*table, db.tables[tab].name);

    /* set the table description */
    db_set_table_description(*table, "");

    if (db.tables[tab].write) {
	db_set_table_delete_priv_granted(*table);
	db_set_table_insert_priv_granted(*table);
    }
    else {
	db_set_table_delete_priv_not_granted(*table);
	db_set_table_insert_priv_not_granted(*table);
    }

    return DB_OK;
}