SQL query to combine tables (n:n) - php

Question

I have these tables:
CATEGORIES:
id
name
KIBE_TRAEGER:
id
name
COUNTIES:
id
region_id
country_id
county_code
county_de
REGIONS:
id
country
region_de
CONTACTS:
id
firstname
surname
company
zipcode
city
region --> =regions.id --> should show regions.region_de
county --> =counties.id --> should show counties.county_de
tel1
tel2
mobile
fax
email1
email2
homepage
categories --> =categories.id BUT in table "contacts" it's written
with ;catnr; (e.g. an entry can have more than 1 entry:
";6;;7;;8;;16;") --> should show categories.name
notes
active
pernr
KIBE_CONTACTS:
id
openinghours
costs
groups
handicapplaces
freeplaces
traeger --> =kibe_traeger.id same as categories ;traegerId; (e.g.";1;;5;") --> should show kibe_traeger.name
and I want to combine all of them to export it to csv.
Btw. i tried my poor queries so far directly in phpmyadmin with left join and inner join but I'm relly poor in SQL stuff and wont learn it anymore :P ...
My code so far (edited according to Matt Cremeen's answers):
Working:
SELECT
contacts.id, contacts.firstname, contacts.surname, contacts.company,
contacts.zipcode, contacts.city, contacts.country, contacts.region,
contacts.county, contacts.tel1, contacts.tel2, contacts.mobile,
contacts.fax, contacts.email1, contacts.email2, contacts.homepage,
contacts.active, contacts.pernr, kibe_contacts.id as contacts_id,
kibe_contacts.openinghours, kibe_contacts.costs, kibe_contacts.groups,
kibe_contacts.handicapplaces, kibe_contacts.freeplaces,
kibe_contacts.traeger, kibe_traeger.id as traeger_id, kibe_traeger.name,
counties.id as counties_id, counties.region_id as region_id,
counties.country_id as country_id, counties.county_code, counties.county_de,
regions.id as regions_id, regions.country as regions_country, regions.region_de
FROM
contacts
INNER JOIN
kibe_contacts ON contacts.id = kibe_contacts.contact_id
INNER JOIN
regions ON contacts.region = regions.id
INNER JOIN
counties ON contacts.county = counties.id
Not working:
INNER JOIN
kibe_traeger ON kibe_contacts.traeger = kibe_traeger.id
INNER JOIN
categories ON contacts.categories = categories.id;
I'm getting a "Null-Result" I think I know why I get this error: because in the column kibe_contacts.traeger and contacts.categories there are more than one values which are separated with ; e.g. an entry can have more than 1 entry: ;6;;7;;8;;16; but in categories.id there is always just a single id e.g. 4.
Is there any solution to query this out?
Last Edit: Solved the second problem by myself: i exported the list and did it with search & replace.
Thanks again to all the helpers!

Answer 1

Assuming that the id field corresponds to each table, you are going to want to join each table on that field. I won't write all of the code here, but it'll start like this
SELECT contacts.id, contacts.firstname, contacts.surname, ...
FROM contacts
INNER JOIN
kibe_contacts
ON contacts.id = kibe_contacts.id
INNER JOIN
regions
on contacts.region_id = regions.id
...

Answer 2

try to use GROUP_CONCAT function of MySQL. Here my sample SQL
I've 2 tables, clientes ('Id' int, 'nome' varchar(50) )
clientes
1 Rafael
2 Jony
3 Smith
and clientes_devices ('Id' int, 'id_cliente' int, 'device' varchar(50) )
clientes_devices
1 1 AsusZenFone
2 1 MotorolaG
3 2 WindowsPhone
Here is the select command
select c.nome, GROUP_CONCAT(DISTINCT d.device SEPARATOR ',') AS Device
from clientes c
join clientes_dispositivos d on (c.id = d.id_cliente)
where c.id = 1
this is the output
Without the function, I got this