[GRASS-SVN] r47599 - grass/trunk/vector/v.colors

[svn_grass at osgeo.org]

Author: martinl
Date: 2011-08-12 03:57:02 -0700 (Fri, 12 Aug 2011)
New Revision: 47599

Added:
   grass/trunk/vector/v.colors/scan_attr.c
Log:
v.colors: add missing file (scan attributes) - see r47598


Added: grass/trunk/vector/v.colors/scan_attr.c
===================================================================
--- grass/trunk/vector/v.colors/scan_attr.c	                        (rev 0)
+++ grass/trunk/vector/v.colors/scan_attr.c	2011-08-12 10:57:02 UTC (rev 47599)
@@ -0,0 +1,84 @@
+#include <grass/vector.h>
+#include <grass/dbmi.h>
+#include <grass/glocale.h>
+
+#include "local_proto.h"
+
+int scan_attr(const struct Map_info *Map, int layer, const char *column_name,
+	      double *fmin, double *fmax)
+{
+    int ctype, is_fp, more, first;
+    double fval;
+    
+    char buf[1024];
+    struct field_info *fi;
+    dbDriver *driver;
+    dbTable *table;
+    dbColumn *column;
+    dbString stmt;
+    dbCursor cursor;
+    dbValue *value;
+     
+    *fmin = *fmax = -1;
+    fi = Vect_get_field(Map, layer);
+    if (!fi)
+	G_fatal_error(_("Database connection not defined for layer %d"),
+		      layer);
+
+    driver = db_start_driver_open_database(fi->driver, fi->database);
+    if (!driver)
+	G_fatal_error(_("Unable to open database <%s> by driver <%s>"),
+		      fi->database, fi->driver);
+    
+    ctype = db_column_Ctype(driver, fi->table, column_name);
+    if (ctype == -1)
+	G_fatal_error(_("Column <%s> not found in table <%s>"),
+		      column_name, fi->table);
+    if (ctype != DB_C_TYPE_INT && ctype != DB_C_TYPE_DOUBLE)
+	G_fatal_error(_("Column <%s> is not numeric"), column_name);
+
+    is_fp = ctype == DB_C_TYPE_DOUBLE;
+
+    G_snprintf(buf, 1023, "SELECT %s FROM %s", column_name, fi->table);
+    G_debug(3, "scan_attr() SQL: %s", buf);
+     
+    db_init_string(&stmt);
+    db_append_string(&stmt, buf);
+    
+    if (db_open_select_cursor(driver, &stmt, &cursor, DB_SEQUENTIAL) != DB_OK)
+	G_fatal_error(_("Unable to select data"));
+    
+    table = db_get_cursor_table(&cursor);
+    column = db_get_table_column(table, 0);
+    value = db_get_column_value(column);
+    
+    /* fetch the data */
+    first = TRUE;
+    while (TRUE) {
+	if (db_fetch(&cursor, DB_NEXT, &more) != DB_OK)
+	    return -1;
+
+	if (!more)
+	    break;
+
+	if (is_fp)
+	    fval = db_get_value_double(value);
+	else
+	    fval = db_get_value_int(value);
+
+	if (first) {
+	    *fmin = *fmax = fval;
+	    first = FALSE;
+	    continue;
+	}
+
+	if (fval <= *fmin)
+	    *fmin = fval;
+	if (fval >= *fmax)
+	    *fmax = fval;
+    }
+
+    db_close_database(driver);
+
+    return is_fp;
+}


Property changes on: grass/trunk/vector/v.colors/scan_attr.c
___________________________________________________________________
Added: svn:mime-type
   + text/x-csrc
Added: svn:eol-style
   + native