Step 1: Set Up Your Supabase Project

• Create a new project in the Supabase dashboard. Visit Supabase and sign up or log in.
• Click on the "New Project" button, give your project a name, and choose a password for your database.
• Wait for Supabase to initialize your project. This may take a few minutes.
• Once the project is ready, you'll be taken to the project's dashboard.

Step 2: Define Your Database Schema

• Go to the "Table Editor" section of the Supabase dashboard.
• Create a new table for storing user roles. Click on "New Table" and enter the name "roles".
• Add columns to the roles table:
  • id: Integer (primary key, auto-incremental)
  • role\_name: Text
  • description: Text
• Save the table by clicking on the "Save" button.
• Create another table for user-role relationships, named "user\_roles":
  • id: Integer (primary key, auto-incremental)
  • user\_id: UUID (Foreign key referencing the users table)
  • role\_id: Integer (Foreign key referencing the roles table)
• Save the table by clicking on the "Save" button.

Step 3: Insert Initial Roles

• Go to the "Table Editor" and select the "roles" table.
• Click on the "Insert Row" button and add roles such as "admin", "editor", and "viewer" with appropriate descriptions.
• Repeat the process to populate your roles table with any other roles you need.

Step 4: Create SQL Policies for Role-Based Access

• Navigate to the "SQL Editor" in the Supabase dashboard.
• Write and execute policies to control data access based on user roles. Here are example policies:
  • Allow only users with the "admin" role to access the entire table:

    CREATE POLICY "Admins can access everything"
              ON public.my\_table
              FOR ALL
              USING (
                EXISTS (
                  SELECT 1
                  FROM public.user\_roles ur
                  JOIN public.roles r ON ur.role\_id = r.id
                  WHERE ur.user\_id = auth.uid()
                  AND r.role\_name = 'admin'
                )
              );

  • Allow users with the "editor" role to insert or update data:

    CREATE POLICY "Editors can insert and update"
              ON public.my\_table
              FOR INSERT, UPDATE
              USING (
                EXISTS (
                  SELECT 1
                  FROM public.user\_roles ur
                  JOIN public.roles r ON ur.role\_id = r.id
                  WHERE ur.user\_id = auth.uid()
                  AND r.role\_name = 'editor'
                )
              );

Step 5: Assign Roles to Users

• Go to the "Table Editor" and select the "user\_roles" table.
• Add entries to assign roles to users. You will need the user’s UUID and the role ID from the "roles" table.
• Click on the "Insert Row" button and fill out the user_id and role_id fields appropriately.

Step 6: Implement Role Checks in Your Application

• Use Supabase client libraries to check for roles within your application code.
• For example, in a JavaScript/Node.js environment:

  import { createClient } from '@supabase/supabase-js';
        const supabase = createClient('your-Supabase-URL', 'your-Supabase-key');
        
    async function isUserAdmin(userId) {
      const { data, error } = await supabase
        .from('user\_roles')
        .select('roles!inner(role\_name)')
        .eq('user\_id', userId)
        .eq('roles.role\_name', 'admin');
      
      if (error) {
        console.error(error);
        return false;
      }
      
      return data.length > 0;
    }</code></pre>
  
    

• Use these checks to conditionally render admin-specific content or enable admin-specific functionalities within your application.