SQL：超越INNER JOIN（由于缺少更好的标题）

Question

Environment:
- PHP 5.3.5
- Oracle 11g database

Table Name: tips_categories

id   category   picture  
1    a          e.jpg  
2    b        f.jpg  
3    c        g.jpg

Table Name: tips

id   tips_categories_id   tip
1    3                       This is a tip.
2    2                       This is another tip.
3    1                       This is yet another tip.

Desired result:

$array_name['tips']
    [0]
        category => a
        picture => e.jpg
        tips
            [0] => This is yet another tip.
    [1]
        category => b
        picture => f.jpg
        tips
            [0] => This is another tip.
    [2]
        category => c
        picture => g.jpg
        tips
            [0] => This is a tip.

Writing one query that returns the desired resuilt is beyond my current knowledge of SQL. An INNER JOIN does not return the desired result. If it cannot be done in one query, I guess the following two queries will have to be used instead:

SELECT id,category,picture FROM tips_categories
SELECT tip FROM tips WHERE tips_categories_id = id

I would greatly appreciate suggestions on how to write this query in one statement. Thank you :-)

Answer 1

Queries don't return hierarchical result sets. So what you are trying to do is impossible.

You can write a simple inner join query, order by id , and then create the array your self iterating over the result set and adding a new entry into the array every time id changes.

Query:

SELECT tips.id,category,picture, tip
  FROM tips_categories
 INNER JOIN tips on (tips_categories_id = id)
 ORDER BY tips.ip

So, your result set will be something like:

 id   category   picture  tip
 1    a          e.jpg    This is yet another tip A01.
 1    a          e.jpg    This is yet another tip A02.
 1    a          e.jpg    This is yet another tip A03.
 2    b          f.jpg    This is another tip B01.
 2    b          f.jpg    This is another tip B02.
 3    c          g.jpg    This is a tip C01.

Provided you have more entries on your tips table.

You iterate with PHP and produce the desired result on your array. It should be pretty simple and straightforward.

Answer 2

Well this:

SELECT c.id, c.category, c.picture, t.tip
FROM tips_categories AS c
INNER JOIN tips AS t
    ON t.tips_categories_id = c.id

Certainly returns the data you want, but tip will simply be a 4th column, not some kind of hierarchy.

What are you using to build your array(s) from the results?