expand/fix vector_db_select() example

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@52211 15284696-431f-4ddb-bdfa-cd5b030d7da7

lib/python/vector.py

@@ -217,8 +217,12 @@ def vector_db_select(map, layer = 1, **kwargs):
     key column value. Example:
 
     \code
-    >>> print grass.vector_select('lakes')['values'][3]
+    >>> print grass.vector_db_select('lakes')['columns']
+    (todo: paste in result)
+    >>> print grass.vector_db_select('lakes')['values'][3]
     ['3', '19512.86146', '708.44683', '4', '55652', 'LAKE/POND', '39000', '']
+    >>> print grass.vector_db_select('lakes', column = 'cat')['values'][3]
+    ['3']
     \endcode
 
     @param map map name
@@ -246,7 +250,7 @@ def vector_db_select(map, layer = 1, **kwargs):
                        **kwargs)
     
     if not ret:
-        error(_('vector_select() failed'))
+        error(_('vector_db_select() failed'))
         return { 'columns' : [], 'values' : {} }
     
     columns = []