如何在MySQL中将三个表连接在一起？

Question

I have a table location that stores countries, provinces and cities. I want when search a city by its id; I can see its province and country too! I have tried too much but I really don't know what exact query I need to write.

My table name is location and these are my fields with example data:

id             enName         localName   type     in_location
1              Iran              ایران    country          0
2              Fars             فارس      province         1
3              shiraz         شیراز       city             2
4              marvdasht        مرو دشت    city            2

I want when I search id = 3 get this results:

country / province / city

Iran / Fars / Shiraz

How I can write this query? I know I must join the table for 3 times but don't know how exactly do that.

The code I have tried :

SELECT 
    in_location ,
    enName 
FROM 
    location 
WHERE 
    id = 12321 as a
INNER JOIN
    SELECT 
        * 
    FROM 
        `fzxit_location` as b 
    on a.in_location = b.id

Answer 1

WHERE statment should always come at the end. I think this is what your looking for. You'll be fixed for relationships with 3 children or less though.

SELECT a.enName, b.enName, c.enName FROM location as a
LEFT JOIN location as b ON a.in_location = b.id
LEFT JOIN location as c ON b.in_location = c.id
WHERE a.id = 3

Answer 2

Although you have not specified other Tables name, you can try this..

select a.countryName, 
       b.proviceName, 
       c.cityName 
from ((country a 
         left join province b on a.countryId = b.countryId) 
         left join city c on a.countryId = c.countryId) 
where id = 3;  

Answer 3

this query may help you!

select from p.province_name,
            ct.country_name,
            c.city_name 
from city as c 
   INNER JOIN provinces as p ON c.province_id=p.province_id 
   INNER JOIN countries as ct ON c.country_id = ct.country_id 
where c.city_id = "requested value";