MySQL INNER JOIN两个表，其中一个表包含具有相同ID的多行

Question

I want to get id's from one table depending on multiple rows from another table with same id. The id's has to only be returned if all rows from the other table matches each row request. My table structure looks like this.

tbl_one 
------------------  
id  companyName 
------------------
1   CompanyOne  
2   CompanyTwo  

tbl_two 
-----------------------------   
id  type        content
-----------------------------
1   zipcode     54321
1   category    Car dealers
2   zipcode     54321
2   category    Supermarkets

I have tried with INNER JOIN, but i can't seem to make it work no matter how i try.

SELECT 
    tbl_one.id FROM tbl_one 
INNER JOIN 
    tbl_two
ON
    tbl_two.id = tbl_one.id 
WHERE
( 
    type = 'zipcode' AND content = '54321'
) 
  AND
( 
    type = 'category' AND content = 'Car dealers' 
)

Can anybody answer me what i'm doing wrong with my query? Thank you :)

Answer 1

Hmm.. try this:-

/*
drop    table tbl_one;
drop    table   tbl_two;

create  table tbl_one(id int, companyName varchar(20)) ;
Insert into tbl_one values
(1,  'CompanyOne'), 
(2,  'CompanyTwo')  ;

create  table tbl_two(id int,type varchar(20), content varchar(20));
insert into tbl_two values
(1 ,  'zipcode'  ,   '54321'),
(1 ,  'category' ,   'Car dealers'),
(2 ,  'zipcode'  ,   '54321'),
(2 ,  'category' ,   'Supermarkets');
*/
SELECT t1.*
FROM  tbl_one t1
WHERE t1.id in (select t2.id from tbl_two t2 where t2.id = t1.id and t2.type = 'zipcode' AND t2.content = '54321')
and     t1.id in (select t3.id from tbl_two t3 where t3.id = t1.id and t3.type = 'category' AND t3.content = 'Car dealers')

Answer 2

The query you provided doesn't work because tbl_two.type cannot equal "zipcode" and "category" at the same time. Perhaps this is what you meant? Note the OR operator on line 7, as opposed to your use of AND ...

SELECT one.id
FROM tbl_one one
JOIN tbl_two two
ON   two.id = one.id
WHERE
     two.type = "zipcode" AND two.content = "54321"
OR   two.type = "category" AND two.content = "car dealers"

OR perhaps you want to find all of the car dealers in 54321, in which case you would need two joins...

SELECT one.id
FROM tbl_one one
JOIN tbl_two one_zip
ON   one_zip.id = one.id
AND  one_zip.type = "zipcode"
AND  one_zip.content = "54321"
JOIN tbl_two one_cat
ON   one_cat.id = one.id
AND  one_cat.type = "category"
AND  one_cat.content = "car dealers"