SQL foreign key to multiple tables

Question

I am creating a health and safety app for 30 different forms; for every question in each document, I need to allow users to add multiple images and enable them to add various actions.

Furthermore, each form needs to be linked to a project.

So far, I have created a Project table, a Site_Weekly_Inspection table (one of the forms) with a foreign key to the project, an Action table with a foreign key site_weekly_inspection and an image table with a foreign key to site_weekly_inspection.

Additionally, in the action and image table, I used action_category and image_category to be able to link the images and actions to the individual questions.

My database so far

I don't want to create a separate image and action table for each form. What would be the MOST CORRECT way of making this database?

Thanks in advance for any suggestions.

Answer 1

You will need table(s) in the middle.

1. Inspection_Action table - lists all possible actions Inspection_Action_id

2. Inspection_Image table (or just Image )- lists all images Inspection_Image_id (PK)

3. Site_Weekly_Inspection_Action Site_Weekly_Inspection_Action_id Inspection_Action_id (FK points to Inspection_Action)

4. If only one image per site / weekly add to Site_Weekly_Inspection table Inspection_Image_id (FK points to Inspection_Image)

5. If more than one image per site /weekly add table Site_Weekly_Inspection_Images Site_Weekly_Inspection_Image_id (PK) Inspection_Image_id (FK points to Inspection_Image)

You will need to figure out how to share images and actions in UI