Hello, I have upgraded MySQL from 4.0.7 to 4.1.9 (OS Win XP SP2) and now I have a problem with empty string comparison.
Test case: CREATE TABLE tb_test ( t1 char(5) NOT NULL default '', t2 char(5) NOT NULL default '' ) ENGINE=MyISAM DEFAULT CHARSET=cp1250 COLLATE=cp1250_czech_cs; INSERT INTO tb_test (t1, t2) VALUES('a', ''); INSERT INTO tb_test (t1, t2) VALUES('b', ' '); SELECT t1, t2, length(t1), length(t2), t2 = '', t2 = ' ', t2 = ' ' FROM tb_test; output: t1 t2 length(t1) length(t2) t2 = '' t2 = ' ' t2 = ' ' a 1 0 0 1 1 b 1 0 0 1 1 I don't know why fields with zero length are not equal to empty string. If I change both fields t1 and t2 to VARCHAR(5) situation is same. Could someone help me to solve this out? Maybe I just missed some variable setting or something like this. Thanks in advance Dusan Pavlica