Question

I’m trying to join 3 tables, somehow do an hierarchical inner join, and get data from the 3rd table. My starting point is the article_number (156118) from the article table. Here are the working sql statements and table structure, but there must be a way to join all this together in one, right?

//  Get the parent task from the article
select task_parent
from article a, tasks t
where a.task_id = t.task_id
and a.article_number = 156118

// Get the task id for the 'Blog' task
select task_id 
from tasks 
where task_parent = 26093 
and task_name like '%blog%'

// Get ALL the blog record
select * 
from blogs
where task_id = 26091

---------Tables------------

* article table *
id | article_number | task_id
1  | 156118         | 26089


* tasks table *
id    | task_name | task_parent
26089 | article   | 26093 
26091 | blogs     | 26093
26093 | Main Task | 26093


* blog table *
id | task_id | content
1  | 102     | blah
2  | 102     | blah 
3  | 102     | blah

-------------

* How do I get all of blog data with 1 SQl statement using just the article_number?

Thanks in advance!

Answer 1

EDIT: Revised answer after rereading question. You need two joins to the task table. One to get the parent of the article’s task and a second to get the blog task with the same parent as the article’s task.

select b.id, b.task_id, b.content
    from article a
        inner join tasks t1
            on a.task_id = t1.task_id
        inner join tasks t2
            on t1.task_parent = t2.task_parent
                and t2.task_name like '%blog%'
        inner join blogs b
            on t2.task_id = b.task_id
    where a.article_number = 156118