thank you but after i read it, I try the second example Pivot table using a JOIN Problem: You have table user_class(user_id int, class_id char(20), class_value char(20)) with these rows: user_id class_id class_value 1 firstname Rogier 1 lastname Marat 2 firstname Jean 2 lastname Smith and you wish create this resultset: user_id firstname lastname 1 Rogier Marat 2 Jean Smith
This query accomplishes the required pivot table via an INNER JOIN: SELECT t1.user_ID, class_value AS firstname, t2.lastname FROM user_class AS t1 INNER JOIN ( SELECT user_ID, class_value AS lastname FROM user_class WHERE class_id='lastname' ) AS t2 ON t1.user_ID=t2.user_ID AND t1.class_id='firstname' but,the query cannot run on my mysql 4.0.23 it returns: SQL 查询 : SELECT t1.user_ID, class_value AS firstname, t2.lastname FROM user_class AS t1 INNER JOIN ( SELECT user_ID, class_value AS lastname FROM user_class WHERE class_id = 'lastname' ) AS t2 ON t1.user_ID = t2.user_ID AND t1.class_id = 'firstname' LIMIT 0 , 30 MySQL 返回: #1064 - You have an error in your SQL syntax. Check the manual that corresponds to your MySQL server version for the right syntax to use near 'SELECT user_ID, class_value AS lastname FROM user_class WHERE c How can i fix it? and thank you for your help. --------------------------------- DO YOU YAHOO!? 雅虎免费G邮箱-中国第一绝无垃圾邮件骚扰超大邮箱