Thread: complex query

I have two tables, users and options.  The common element between the
tables is "username".  I want to select the "email" from "user" but only
if the "mailing_list" option is set to true in the "options" table.

Here are the tables:

select username, email from users;  username    |             email
---------------+--------------------------------joe           | joe@yahoo.comheidi         | heidi@localhostpayday
 | brant@localhostfake          | fake@localhostmattgerg      | mattgerg@users.sourceforge.netgod           |
god@heaven.org

select username, mailing_list from options;  username    | mailing_list
---------------+--------------payday        | tgod           | tfake          | tmattgerg      | t


I want to write a query that will return the emails of only the users
payday, god, fake, and mattgerg.

Is this at all possible?  I am new to sql, and I am having trouble.

--Matt



-- 
Matt Gerginski <mattgerg@users.sourceforge.net>

* Matt Gerginski <mattgerg@users.sourceforge.net> [03.03.2003 19:11]:
> I have two tables, users and options.  The common element between the
> tables is "username".  I want to select the "email" from "user" but only
> if the "mailing_list" option is set to true in the "options" table.
>
> Here are the tables:
>
> select username, email from users;
>    username    |             email
> ---------------+--------------------------------
>  joe           | joe@yahoo.com
>  heidi         | heidi@localhost
>  payday        | brant@localhost
>  fake          | fake@localhost
>  mattgerg      | mattgerg@users.sourceforge.net
>  god           | god@heaven.org
>
> select username, mailing_list from options;
>    username    | mailing_list
> ---------------+--------------
>  payday        | t
>  god           | t
>  fake          | t
>  mattgerg      | t
>
>
> I want to write a query that will return the emails of only the users
> payday, god, fake, and mattgerg.
>
> Is this at all possible?  I am new to sql, and I am having trouble.
>

select u.username, u.email from users as u, options as o where u.username =
o.username and o.mailing_list = true;


You'd better read some book on SQL.

--

Victor Yegorov