FAQs & Troubleshooting

Common Questions & Issues

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Prisma Connection Errors

Problem: Prisma can throw errors like:

• prepared statement already exists
• Can't reach database server at ...
• Timed out fetching a new connection from the connection pool

Solution:

1. Append ?pgbouncer=true to your Supabase pooling DATABASE_URL to disable problematic prepared statements.
2. Increase timeouts as needed:

   DATABASE_URL="...pgbouncer=true&connect_timeout=30&pool_timeout=30"

3. Monitor your DB connection limits—optimize slow queries and scale your Supabase instance if needed.

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PrismaClient in Browser / Edge Runtime

Issue: Running PrismaClient in the browser or edge runtime causes errors.

Recommendation:

• Only instantiate PrismaClient in back-end or server-side code.
• Avoid using Prisma APIs in app components with 'use client'.
• Use tRPC back-end procedures to safely expose data.

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Supabase Auth Issues

Problem: Users aren’t being created in your User Prisma model after signup.

Fix:

• Use Supabase triggers to sync auth users into your public schema.

  CREATE FUNCTION handle_new_user() RETURNS trigger AS $$
  BEGIN
    INSERT INTO public."User"(id) VALUES (NEW.id);
    RETURN NEW;
  END;
  $$ LANGUAGE plpgsql;
  
  CREATE TRIGGER sync_user
    AFTER INSERT ON auth.users
    FOR EACH ROW EXECUTE FUNCTION handle_new_user();

• Ensure your Prisma User model matches this shape.

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tRPC Debugging: Why am I getting any everywhere?

Solution:

• Enable "strict": true in tsconfig.json.
• Ensure your @trpc/* versions are aligned.
• Add this in .vscode/settings.json to use the workspace TypeScript:

  {
    "typescript.tsdk": "node_modules/typescript/lib",
    "typescript.enablePromptUseWorkspaceTsdk": true
  }

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Performance: Over-reliance on use client

Issue: Too many client-side data fetches slow down SSR and increase bundle sizes.

Tip:

• Fetch data in server components or via getServerSideProps, then pass it to client components via initialData.
• Use .createCaller() on the server to pre-populate data and reduce client JS.

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tRPC vs Next.js Server Actions

Question: Should I use tRPC or Next.js Server Actions?

Insight:

• tRPC provides type-safe client-server APIs ideal for monolithic TypeScript apps.
• Next.js Server Actions are simpler but don’t offer the same level of type inference or ecosystem support.
• For your marketplace, tRPC offers more benefits and flexibility.

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Still Stuck?

Feel free to:

• Re-read sections: Database, API (tRPC), or Authentication
• Open an issue in your project repo
• Join Supabase / tRPC Discord communities for support