Hello all, Following my previous mail about FULL OUTER JOIN, i tried to deal with UNION but i get some weird problems. I've created two temporary table, here their content :
mysql> select * from T3; +---------+-------------+----------+ | ver_ref | server | ver_real | +---------+-------------+----------+ | 11 | bar | NULL | | 11 | foo | 10 | | 11 | foo | 10 | | 11 | aaa | NULL | +---------+-------------+----------+ mysql> select * from T4; +---------+-------------+----------+ | ver_ref | server | ver_real | +---------+-------------+----------+ | NULL | kkkk | 10 | | 11 | foo | 10 | | 11 | foo | 10 | | NULL | bbbb | 10 | | NULL | cccc | 10 | | NULL | dddd | 10 | | NULL | eeee | 10 | | NULL | ffff | 10 | | NULL | gggg | 10 | | NULL | hhhh | 10 | | NULL | iiii | 10 | | NULL | jjjj | 10 | +---------+-------------+----------+ And here is the result of both with UNION statement : mysql> select * from T4 union select * from T3; +---------+-------------+----------+ | ver_ref | server | ver_real | +---------+-------------+----------+ | NULL | kkkk | 10 | | 11 | foo | 10 | | NULL | bbbb | 10 | | NULL | dddd | 10 | | NULL | eeee | 10 | | NULL | ffff | 10 | | NULL | gggg | 10 | | NULL | hhhh | 10 | | NULL | iiii | 10 | | NULL | jjjj | 10 | | NULL | kkkk | 10 | | 11 | bar | | | 11 | aaa | | +---------+-------------+----------+ Arg!! why is there no NULL values instead of blank place in the ver_real column? When making the query as : select * from T3 union select * from T4; i obtain the opposite. NULL values in the previous array are replaced by blank values, and blank values, replaced by NULL ones. What can be the problem come from? Thank's for all your ideas. Vincent -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
