how to create a view from three tables

Question

I have problem with getting combined records from 3 tables.

Here is the structure of the tables

CREATE TABLE IF NOT EXISTS `adds` (
`addid` int(11) NOT NULL AUTO_INCREMENT,
`addtypeid` varchar(45) NOT NULL,
`addcreatedon` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
`addtitle` varchar(255) DEFAULT NULL,
`addtext` text NOT NULL,
PRIMARY KEY (`addid`)
) ENGINE=InnoDB  DEFAULT CHARSET=utf8 AUTO_INCREMENT=40 ;


CREATE TABLE IF NOT EXISTS `adds_filters` (
`addfilterid` int(11) NOT NULL AUTO_INCREMENT,
`addid` int(11) NOT NULL,
`filterid` int(11) NOT NULL,
PRIMARY KEY (`addfilterid`)
) ENGINE=InnoDB  DEFAULT CHARSET=utf8 AUTO_INCREMENT=40 ;


CREATE TABLE IF NOT EXISTS `categories_filters` (
`filterid` int(11) NOT NULL AUTO_INCREMENT,
`catid` varchar(45) NOT NULL,
`filtername` varchar(45) NOT NULL,
`sorder` int(11) DEFAULT NULL,
`visible` int(11) DEFAULT NULL,
PRIMARY KEY (`filterid`)
) ENGINE=InnoDB  DEFAULT CHARSET=utf8 AUTO_INCREMENT=230 ;

Adds have one to many relationship with adds_filters. That is, one add can have more then one filter.

What I need is the following:

I would like to create a view which when select * would return all rows from adds, together with filterid(s) and respective filtername(s). Please note that one add may have many filterid(s)

Can anyone help me with this?

Regards

Answer 1

create view v1 as
select adds.addid as addid, categories_filters.filtername as filtername, categories_filters.filterid as filterid  
from adds inner join adds_filters on adds.addid = adds_filters.addid
inner join categories_filters on categories_filters.filterid = adds_filters.filterid

Answer 2

You do not need a view.

I think you want to use a combination of LEFT OUTER JOIN and GROUP_CONCAT() . That way you will get 1 result for each row in the adds table, along with a list of related filter_ids and filter_names, if any.

Something like this:

select adds.addid, adds.addtypeid, adds.addcreatedon, adds.addtitle, adds.addtext,
  group_concat(adds_filters.filterid) as filter_ids, 
  group_concat(categories.filtername) as filter_names
from adds
  left outer join adds_filters on adds_filters.addid = adds.addid
  left outer join categories_filters on categories_filters.filterid = adds_filters.filterid
group by adds.addid, adds.addtypeid, adds.addcreatedon, adds.addtitle, adds.addtext;