Question

I have a basic level of SQL understanding, hence needing help and thanks in advance to those who reply.

I have 2 tables, one table contains Headings and Options that can be selected under those headings. The other table links to the actual data references of that table to reference the heading name and option.

I am trying to perform a SQL query to join these tables, then reference the parent/child ID’s in one table to pull the heading+selected option from the other table, but all I get back is the ID numbers. I’ve created a image that should explain what I’m trying to get back as a result.. and failing at badly!

This image here will explain:

NOTE – Above, where I say not 18 and 20, I can make my result show the ID numbers.. but not the correct info from the Parent title and Child title. (Server Support – Site Visits Chargable)

This is where I’ve gotten to with the SQL:

    SELECT custom_def_organizations.title
    FROM custom_data_organizations
    INNER JOIN organizations
    ON custom_data_organizations.organization_id = organizations.id
    INNER JOIN custom_def_organizations
    ON custom_def_organizations.parent_id = custom_data_organizations.root_field_id 
    AND custom_def_organizations.id = custom_data_organizations.field_id

Answer 1

First query to join parent and child, without custom_data_organization but using the implied hierarchy:

SELECT parent.id, child.id
    FROM custom_def_organizations AS parent
    JOIN custom_def_organizations AS child
        ON (child.parent_id = parent.id);

This will return:

18  19
18  20
18  21
18  22
18  23

Now to fetch the other info:

SELECT parent.id, child.id, CONCAT(parent.title, ' - ', child.title) AS title
    FROM custom_def_organizations AS parent
    JOIN custom_def_organizations AS child
        ON (child.parent_id = parent.id);

This will return:

18  19  Server Support - Yes
18  20  Server Support - Site Visits Chargeable
18  21  Server Support - Site Visits Included
18  22  ...
18  23

The same concept but with custom_data_organizations driving the JOIN:

SELECT cdo.id, CONCAT(parent.title, ' - ', child.title) AS title
    FROM custom_data_organizations AS cdo
    JOIN custom_def_organizations AS parent
        ON (cdo.root_field_id = parent.id)
    JOIN custom_def_organizations AS child
        ON (cdo.field_id = child.id);

This will return:

    85    Server Support - Site Visits Chargeable
    ...