[sqlite] SELECT (...) GROUP BY not returns!

[Adam Dziendziel]

When I execute:

SELECT COUNT(*) FROM drzewo_towar WHERE lft > 13 AND rgt < 14 GROUP BY towar

on the table:

CREATE TABLE drzewo_towar (

        id INTEGER PRIMARY KEY,

        nazwa TINYTEXT,
        towar INTEGER,

        lft INTEGER,
        rgt INTEGER,
        dpt INTEGER

);
INSERT INTO "drzewo_towar" VALUES(1, 'Wszystkie', NULL, 1, 16, 0);
INSERT INTO "drzewo_towar" VALUES(2, 'Pusta', NULL, 2, 5, 1);
INSERT INTO "drzewo_towar" VALUES(3, 'Z zawartoscia', NULL, 6, 15, 1);
INSERT INTO "drzewo_towar" VALUES(4, 'Grupa 1', NULL, 7, 12, 2);
INSERT INTO "drzewo_towar" VALUES(5, 'Grupa 2', NULL, 13, 14, 2);
INSERT INTO "drzewo_towar" VALUES(8, NULL, 3, 8, 9, 3);
INSERT INTO "drzewo_towar" VALUES(9, NULL, 5, 3, 4, 2);
INSERT INTO "drzewo_towar" VALUES(10, NULL, 5, 10, 11, 3);

the engine doesn't return the value (the above query should return 0).

Why?

--
Regards,
Adam