GUI patterns to edit data with many-to-many relationship

Question

I often run into a situation where I need to come up with a GUI to edit data that has a n:m relationship. I'm looking for user friendly GUI ideas.

[table1]
   |
  /|\
[table2]
  \|/
   |
[table3]

Usually the GUI resembles something like this:

---

Grid that shows all items from table1

Add table3 item... _{(shows modal window with table3 items)}

---

Grid that shows all items from table3

---

After the user picked a table3 item, I add a new row to table2 and refresh the grids.

Disadvantages:

• You can only add table3 items to table1, and not the other way around;
• You can only browse table1 items and see related table3 items;
• I need to have one filtered grid of table3 items, and a similar one to pick new items;

My question:

Does anyone know a better way to visually browse and edit data that has a n:m relationship? Or any nice patterns that I could "steal" from existing software packages?

Answer 1

Solution 1

If the data sets are not too big, use a table and allow users to place checks in cells (table 1 is X axis and table3 is Y axis).

You can probably do this for larger table1/3 data sets as long as you allow users to filter or otherwise limit which values are displayed on x and y axis.

Solution 2

To quote from this page, "A many-to-many relationship is really two one-to-many relationships with a junction/link table".

As such, you can, as one solution, simply take your own solution and resolve your first 2 dis-advantages by having screens/dialogs to go table 1=>3 as well as 3=>1.

Not a perfect solution but at least provides all the needed functionality

Solution 3

Somewhat similar to your own solution:

1. Show a table based on table1, with:

   B. col1 containing table1 elements

   C. col2 containing a list of all elements from table3 already associated with this element from table1.

   The list can be either horizontal if there are usually few elements associated, or vertical (scrollable) if horizontal to too wide.

   The important part is that every displayed element from table3 has a "delete" icon (x) next to it to allow removal quickly.

2. Allow choosing which element from table1 you want to add mappings to.

   There are 2 ways of doing this - either add a checkbox to every row in your table, and have one button labeled "add relationships to selected rows" (wording needs improvement), or simply have a 3-rd column in the table, containing button/link for adding relationships to that individual row.

   The former is a good idea if the user is likely to often add exactly the same set of element from table3 to several rows from table1.

3. When "Add" button/link is clicked, you display a filterable multi-select list of elements from table3, with "add selected" button.

4. As in your solution (see my #2), this is a-symmetrical so you should implement a mirror UI for mapping from table3 to table1 if needed.

Answer 2

This is an old question, but as I faced the same problem again just now, I came up with this:

1. 2 grids, side by side, showing table1 and table3 items, with paging, if necessary.
2. Both grids have a top toolbar which allows filtering by a value from the opposite table. Depending on your data and your gui framework, it can be a drop-down combo grid, or an auto-complete text input.
3. Both grids have checkboxes (last or first column)
4. Both grids contain an inline button/action on each row, to automatically filter the other grid on that item.
5. Only one grid is shown/marked as "active" or "master" at any given time (to make it clear to the user, which side of the relationship they are viewing/controlling).

When you select an item in grid1, grid1 becomes active and all items in the other grid have checkboxes ticked if they are associated with the selected item.

Vice versa, when you select an item in grid2 (table3), grid2 becomes active, all checkboxes in grid2 are blank (or dimmed-out) and checkboxes in grid1 indicate an association with the selected item.

The filtering part is made easier based on the inline button described in step 4.

I believe this solution would satisfy all your requirements.

Answer 3

Here's a possible solution, given in the form of an employees-to-projects m:m relationship. Each employee can work on many projects, each project can involve many employees.

From left to right, you show the following:

A panel showing the details of the currently selected employee.

A list of all employees, where each item in the list shows the employee's name as a clickable link or button (to display details in the detail panel). At the head of the list is a toggle button which filters the projects list to only those associated with the currently selected employee. At the foot of the list is a button to add a new employee, which display an empty details panel ready to accept input.

A vertical space in the middle with a single "Link" button allowing the user to link the currently selected employee with the currently selected project. Clicking this button would open a dialog allowing the user to enter details of the link (i.e. how long the employee is assigned, what role the eployee will play, etc).

A list of all projects, where each item in the list shows the project's name as a clickable link or button (to display details in the detail panel). At the head of the list is a toggle button which filters the employees list to only those associated with the currently selected projet. At the foot of the list is a button to add a new project, which display an empty details panel ready to accept input.

A panel showing the details of the currently selected project.

Obviously, you'd have to limit the size of the details panels, maybe by only showing the details relevant to the m:m relationship. You might even add a button on the details panel to open a more detailed pop-up window, or you might do away with the details panel altogether, if you're mainly interested in managing the links. This UI would work really well on wide-aspect screens.

HTH! Klay

Answer 4

Let me use the One Customer Has 0 or many Orders relationship example. If user wants to see the Orders of particular form I would suggest the following Use Case:

1. The User clicks the Search Customer link:
2. The System presents the Search Customer Form having the search criteria to filter on
3. The User fills the Search Criteria and hits the Search button
4. The System presents a list of the Customer ... by the matched criteria
5. The User hits the Open button in front of A Customer
6. The System presents the Customer ( in totally new page with "Back to Search Button ")

The new Page has 3 panels - 1 panel for Customer Details , second Panel for the list of Orders and 3 panel which gets populated when a Order is clicked. If the number of Orders is greater than 20 I would put a Search Orders link which guides to entirely new Search form for Orders with a predefined CustomerId fixed with the current CustomerId selected.