bulduing a select to get excluded datas
Date: 4 Apr 2005 18:10:10 -0700
Message-ID: <1112663410.662034.146260_at_z14g2000cwz.googlegroups.com>
Hello, I have a problem because I am trying to find results from a select statement, where the datas from the first table are the ones that are NOT included in the second tables.
I have a table containing the list of known users: users_list
map_id, ->id refering to another table rank, ->rank of the user
other datas...
several entries can have the same map_id, the key of this table is the association of (map_id, rank)
and I the table of users : users
map_id,
datas about the user.... -> several rows of datas for this particular
user
The table "users" can have users that are not yet known, therefore they are not in the "users_list" table
I want to write a web page that takes any users that is not known yet, so I can fill the missing datas and add the user in the users_list The difficulty is that one known user can have several ranks so to display the list of users that are not yet known, I tried the following statement:
select users.map_id,users_list.rank from users,users_list where
users.map_id!=users_list.map_id
but it doesn't work! I get multiple entries of "map_id" joined with
"rank"
what I want is the list of all references "map_id" in the table "users"
for which the map_id is not included in the table "users_list"
If anyone can help me, I'd be very thankful, because I'm lost! Received on Tue Apr 05 2005 - 03:10:10 CEST