Database design for dentist app

Question

So I'm doing a web app for my sister, as she recently received her degree on odontology.

I'm having a bit of a struggle with the database design though...

I'm obviously supposed to have an appointment table (tbl_appointment), appointments may have treatments associated to them, and those treatments all have different attributes (columns).

So I'm thinking I should have a tbl_appointment and also a tbl_treatment, I'm not sure on how to link those tables as to have multiple treatment types, with different treatment parameters and save the treatment data related to the appointment.

What do you think would be a good approach to this? I already have something drawn out but it definitely doesn't seem good as I end up having one table for each treatment type and I don't think thats the best solution.

EDIT

As this wasn't clear enough, here's a screenshot of how my actual db looks like.

If I implement the treatments as I did the periodontogram, I'm gonna end up with 20 tables one for each treatment type. I want to avoid that!

EDIT

@Ian Kenney, so if I got what you were suggesting right, this is how the portion of the database we're discussing should look like...

Am I right? Don't pay attention to the relation types as they're all 1:1, I am aware I should use some M:N in there, but it was just for the example.

Answer 1

One approach for the various treatment types would be to look at the attributes that are common between them, for example it may include:

• name
• description
• price
• time_required

These become the columns of tbl_treatment

Then use an additional table for other (treatment specific) attributes tbl_treatment_attributes with a structure like:

• treatment_id
• attribute_name
• attribute_value

Each treatment could have many additional attributes, the acceptable attributes (including defaults) could be managed in tbl_treatment_defaults

• treatment_id
• attribute_name
• field_type
• validations
• default_value

EDIT

+-------------------+              +--------------------+
| tbl_treatment     |              | tbl_treatment_type |
+===================+              +====================+
|*treatment_id      |              |*treatment_type_id  |
|+treatment_type_id |<-------------| treatment_name     |
|  ......           |              | ......             |
+-------------------+              +--------------------+
         |                                   |
         v                                   v
+--------------------------+       +------------------------+
| tbl_treatment_attributes |       | tbl_treatment_defaults |
+==========================+       +========================+
|*treatment_id             |       |*treatment_type_id      |
| attribute_name           |<------| attribute_name         |
| attribute_value          |       | default_value          |
| ........                 |       | .......                |
+--------------------------+       +------------------------+

Answer 2

The tbl_appointment appointment table should only have appointment data and patientId (foreign key into your tbl_Patient table)

You should have a 3rd table called tbl_Visit that contains a foreign key into the tbl_appointment. Then another table called tbl_Visit_treatment that has VisitId and TreatmentId. So this tbl_Visit_treatment is the many-to-many relationship table that tracks all the treatments done in each visit.

As for TreatmentType(s), that will simply be a type table called tbl_TreatmentType with ID, Name, Code and Description fields. The TreatmentId will be a foreign key in the tbl_Treatmenttable.