85 lines
3.3 KiB
ReStructuredText
85 lines
3.3 KiB
ReStructuredText
.. _relations:
|
|
|
|
Relations
|
|
=========
|
|
|
|
phpMyAdmin allows relationships (similar to foreign keys) using MySQL-native
|
|
(InnoDB) methods when available and falling back on special phpMyAdmin-only
|
|
features when needed. There are two ways of editing these relations, with the
|
|
*relation view* and the drag-and-drop *designer* -- both of which are explained
|
|
on this page.
|
|
|
|
.. note::
|
|
|
|
You need to have configured the :ref:`linked-tables` for using phpMyAdmin
|
|
only relations.
|
|
|
|
Technical info
|
|
--------------
|
|
|
|
Currently the only MySQL table type that natively supports relationships is
|
|
InnoDB. When using an InnoDB table, phpMyAdmin will create real InnoDB
|
|
relations which will be enforced by MySQL no matter which application accesses
|
|
the database. In the case of any other table type, phpMyAdmin enforces the
|
|
relations internally and those relations are not applied to any other
|
|
application.
|
|
|
|
Relation view
|
|
-------------
|
|
|
|
In order to get it working, you first have to properly create the
|
|
[[pmadb|pmadb]]. Once that is setup, select a table's "Structure" page. Below
|
|
the table definition, a link called "Relation view" is shown. If you click that
|
|
link, a page will be shown that offers you to create a link to another table
|
|
for any (most) fields. Only PRIMARY KEYS are shown there, so if the field you
|
|
are referring to is not shown, you most likely are doing something wrong. The
|
|
drop-down at the bottom is the field which will be used as the name for a
|
|
record.
|
|
|
|
Relation view example
|
|
+++++++++++++++++++++
|
|
|
|
.. image:: images/pma-relations-relation-view-link.png
|
|
|
|
.. image:: images/pma-relations-relation-link.png
|
|
|
|
Let's say you have categories and links and one category can contain several links. Your table structure would be something like this:
|
|
|
|
- `category.category_id` (must be unique)
|
|
- `category.name`
|
|
- `link.link_id`
|
|
- `link.category_id`
|
|
- `link.uri`.
|
|
|
|
Open the relation view (below the table structure) page for the `link` table and for `category_id` field, you select `category.category_id` as master record.
|
|
|
|
If you now browse the link table, the `category_id` field will be a clickable hyperlink to the proper category record. But all you see is just the `category_id`, not the name of the category.
|
|
|
|
.. image:: images/pma-relations-relation-name.png
|
|
|
|
To fix this, open the relation view of the `category` table and in the drop down at the bottom, select "name". If you now browse the link table again and hover the mouse over the `category_id` hyperlink, the value from the related category will be shown as tooltip.
|
|
|
|
.. image:: images/pma-relations-links.png
|
|
|
|
Designer
|
|
--------
|
|
|
|
The Designer feature is a graphical way of creating, editing, and displaying
|
|
phpMyAdmin relations. These relations are compatible with those created in
|
|
phpMyAdmin's relation view.
|
|
|
|
To use this feature, you need a properly configured :ref:`linked-tables` and
|
|
must have the :config:option:`$cfg['Servers'][$i]['table_coords']` configured.
|
|
|
|
To use the designer, select a database's structure page, then look for the
|
|
:guilabel:`Designer` tab.
|
|
|
|
To export the view into PDF, you have to create PDF pages first. The Designer
|
|
creates the layout, how the tables shall be displayed. To finally export the
|
|
view, you have to create this with a PDF page and select your layout, which you
|
|
have created with the designer.
|
|
|
|
.. seealso::
|
|
|
|
:ref:`faqpdf`
|