How to fix P1014: The underlying model does not exist in Prisma

First, check your schema.prisma file to confirm the model definitions are correct:

// Example: Check that your model is properly defined
model User {
  id    Int     @id @default(autoincrement())
  email String  @unique
  name  String?
}

Ensure the model causing the error is actually defined in your schema and spelled correctly.

The most common fix is to apply your migrations to create the missing database tables:

# For development environments
npx prisma migrate dev

# For production environments (applies migrations without prompts)
npx prisma migrate deploy

This will create all tables defined in your schema that don't yet exist in the database. If you're using db push instead of migrations:

npx prisma db push

This syncs your schema directly to the database without creating migration files.

If you have multiple migration files, ensure they're in the correct chronological order. Each migration should build upon previous migrations:

# List your migrations directory
ls -la prisma/migrations/

Migration folders are timestamped. If you see a migration that modifies a table (e.g., ALTER TABLE) before the migration that creates it (e.g., CREATE TABLE), you have an ordering issue.

To fix:
1. Delete the problematic migration files
2. Reset your database: npx prisma migrate reset
3. Recreate migrations in the correct order: npx prisma migrate dev --name your_migration_name

If the shadow database is causing issues, you can force Prisma to recreate it:

# This resets your development database and recreates the shadow database
npx prisma migrate reset

# Then apply migrations fresh
npx prisma migrate dev

Warning: migrate reset will delete all data in your development database. Only use this in development environments.

Check if the migration tracking table exists in your database:

-- For PostgreSQL
SELECT * FROM _prisma_migrations;

-- For MySQL
SHOW TABLES LIKE '_prisma_migrations';

If this table is missing or in the wrong schema (PostgreSQL), Prisma cannot track which migrations have been applied. To fix:

# Recreate the migrations table
npx prisma migrate resolve --applied <migration_name>

For PostgreSQL with custom schemas, ensure your schema.prisma includes:

datasource db {
  provider = "postgresql"
  url      = env("DATABASE_URL")
  schemas  = ["public", "your_custom_schema"]
}

After fixing your migrations and database state, always regenerate your Prisma Client:

npx prisma generate

This ensures your application code has the latest type definitions matching your database schema. Restart your development server after generating to pick up the changes.