I use the following query:

select * from A LEFT JOIN B on ( A.t_id != B.t_id)

to get all the records in A that are not in B.

The results are fine except when table B is completely empty, but then I do not get any records, even from table A.

Later

It wont work yet!

CREATE TABLE IF NOT EXISTS T1 ( id int(11) unsigned NOT NULL AUTO_INCREMENT, title varchar(50) CHARACTER SET utf8 COLLATE utf8_unicode_ci NOT NULL, t_id int(11) NOT NULL, PRIMARY KEY (id) ) ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=3 ;

--

-- Dumping data for table T1

INSERT INTO T1 (id, title, t_id) VALUES (1, 'apple', 1), (2, 'orange', 2);

--

-- Table structure for table T2

CREATE TABLE IF NOT EXISTS T2 ( id int(11) NOT NULL AUTO_INCREMENT, title varchar(50) CHARACTER SET utf8 COLLATE utf8_unicode_ci NOT NULL, t_id int(11) NOT NULL, PRIMARY KEY (id) ) ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=2 ;

--

-- Dumping data for table T2

INSERT INTO T2 (id, title, t_id) VALUES (1, 'dad', 2);

Now I want to get all records in T1 that do not have a corresponding records in T2

I try

SELECT * FROM T1 LEFT OUTER JOIN T2 ON T1.t_id != T2.t_id

and it won't work