How to JOIN on different tables based on column value

How to JOIN on different tables based on column value

PROBLEM:

ads table

phones table

cars table

i have 3 tables ads,cars and phones.

i want to join tables is based on category in ads table.

and i tried this query but no luck,any helps?

SELECT *
  FROM `ads` 
  JOIN `ads.category` ON `ads.id` = `ads.category.id`

** i cant add comment any of your post,but i want it to be automatic based on category in ads table.

for example :- if in table have phones category,i will automatic join phones table then

SELECT *
  FROM `ads` 
  JOIN `phone` ON `ads.id` = `phone.id`

if in table have cars category,i will automatic join cars table

SELECT *
  FROM `ads` 
  JOIN `cars` ON `ads.id` = `cars.id`

SOLUTION:

to get the cars:

SELECT *
FROM ads JOIN cars ON ads.ID = cars.ID

to get the phone:

SELECT *
FROM ads JOIN phones ON ads.ID = phones.ID

to get both use a UNION:

SELECT ads.ID, ads.Title, ads.Desc, ads.category, 'Car' AS AdType, cars.Year AS Col1, cars.cc AS Col2, cars.transmission AS Col3
FROM ads JOIN cars ON ads.ID = cars.ID
UNION ALL SELECT ads.ID, ads.Title, ads.Desc, ads.category, 'Phone' AS AdType, phone.Model AS Col1, phone.Color AS Col2, '' AS Col3
FROM ads JOIN phones ON ads.ID = phones.ID

note: i would advise you to setup foreign keys in your cars and phones tables, to reference the ads.ID instead of using the ID field (Primary key?) of the child tables

For more about the UNION AND UNION ALL.