problem with query two different tables with foreign key relations I am having a problem with querying two tables with different foreign key relations... My first query works fine but when adding another table with a different set of relations I am having a problem... Can some one point me in the right direction.

First Query works:

select `title`,`txt`,`img`
from `content_m2m`
inner join `content`
on `content_m2m`.`content` = `content`.`cid`
inner join `links`
on `content_m2m`.`links` = `links`.`lid`
inner join `category`
on `content_m2m`.`category` = `category`.`catid`
where `content_m2m`.`keywords` like '%test%';


Second query that I am stuck when adding another table:

select `title`,`txt`,`img`
from `content_m2m`
inner join `content`
on `content_m2m`.`content` = `content`.`cid`
inner join `links`
on `content_m2m`.`links` = `links`.`lid`
inner join `category`
on `content_m2m`.`category` = `category`.`catid`
where `content_m2m`.`keywords` like '%test%' OR (
select `firstname`,`lastname`,`email`,`mi`,`dName`,`phnumber`
from `staff`
inner join `departments`
on `staff`.`department` = `departments`.`did`
inner join `phones`
on `staff`.`phone` = `phones`.`pid`
where `staff`.`keywords` like '%test%');
If you need to combine result sets from different tables, use the UNION operator with two queries. Since the sets have different and unrelated column names, you will need to select a placeholder (usually NULL) in each query for columns in the other query:

select `title`,`txt`,`img`,
NULL, NULL, NULL, NULL, NULL, NULL
from `content_m2m`
inner join `content`
on `content_m2m`.`content` = `content`.`cid`
inner join `links`
on `content_m2m`.`links` = `links`.`lid`
inner join `category`
on `content_m2m`.`category` = `category`.`catid`
where `content_m2m`.`keywords` like '%test%'
UNION
select NULL, NULL, NULL,
`firstname`,  `lastname`, `email`, `mi`, `dName`, `phnumber`
from `staff`
inner join `departments`
on `staff`.`department` = `departments`.`did`
inner join `phones`
on `staff`.`phone` = `phones`.`pid`
where `staff`.`keywords` like '%test%';