Hi all, I have a trouble with multiple-column indexes, I will try to describe it with an example. Suppose I have a table like the following one: +------------+------------+-------+-----------+ | id_example | x_uno | x_due | x_desc | +------------+------------+-------+-----------+ | 1 | 2004-01-01 | 2 | qweqe | | 2 | 2004-01-01 | 3 | qqqqqqqqq | | 3 | 2004-01-01 | 4 | weqweqweq | | 4 | 2004-01-02 | 1 | QWEQWE | | 5 | 2004-01-02 | 2 | AAAAA | | 6 | 2004-01-02 | 3 | aaaaa | | 7 | 2004-01-02 | 4 | aaaa | | 8 | 2004-01-03 | 2 | 0 | | 9 | 2004-01-03 | 5 | qqqq | +------------+------------+-------+-----------+ where id_example is the Primary Key, and there is an Index on x_uno, x_due. How can I write a query in order to select records using a combination of columns x_uno and x_due? I would like, for example, to get the records starting from row number 6 (without, of course, working with the primary key, where the numbers could not necessarily be sorted as here): +------------+------------+-------+-----------+ | id_example | x_uno | x_due | x_desc | +------------+------------+-------+-----------+ | 6 | 2004-01-02 | 3 | aaaaa | | 7 | 2004-01-02 | 4 | aaaa | | 8 | 2004-01-03 | 2 | 0 | | 9 | 2004-01-03 | 5 | qqqq | +------------+------------+-------+-----------+ In fact, a select with the following syntax: SELECT * FROM `example` where x_uno>=20040102 and x_due >= 3 ORDER BY x_uno ASC, x_due ASC does not return me row number 8 (as it is 2<3 on column x_due). Of course I could use a new (redundant) column composed by the two ones, so that I have: +------------+---------------+----------+-------+-----------+ | id_example | x_composed | x_uno | x_due | x_desc | +------------+---------------+----------+-------+-----------+ | 6 | 20040102003 | 2004-01-02 | 3 | aaaaa | | 7 | 20040102004 | 2004-01-02 | 4 | aaaa | | 8 | 20040103002 | 2004-01-03 | 2 | 0 | | 9 | 20040103005 | 2004-01-03 | 5 | qqqq | +------------+---------------+----------+-------+-----------+ Anyway, I would not like to choose such a solution, as this situation would be frequent with the tables I am going to use. Is there something I am missing with SQL syntax?
Thank you, Rocco Castino M.C.S. Computer & Software S.r.l. -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
