How to fix P2016: Query interpretation error in Prisma

P2016: Query interpretation error. Could not interpret query at path: user.posts.comments

P2016: Query interpretation error. Ambiguous reference to field: 'author'

// Problematic query with ambiguous references
const problematic = await prisma.user.findMany({
  include: {
    posts: {
      include: {
        author: true, // Which author? User author or Post author?
        comments: {
          include: {
            author: true // Ambiguous reference
          }
        }
      }
    }
  }
});

// Solution: Use explicit aliases or separate queries
const posts = await prisma.post.findMany({
  include: {
    author: true,
    comments: {
      include: {
        author: true
      }
    }
  },
  where: {
    userId: userId
  }
});

npx prisma db pull

// Problem: Circular dependency
model User {
  id       String @id @default(cuid())
  posts    Post[]
  // Circular reference
  manager  User?  @relation("Manager", fields: [managerId], references: [id])
  managerId String?
}

// Solution: Break the circular dependency or use explicit relation names

// Instead of ambiguous nested includes:
const ambiguous = await prisma.user.findMany({
  include: {
    posts: {
      include: {
        comments: {
          include: {
            author: true // Which author? Comment author or Post author?
          }
        }
      }
    }
  }
});

// Use explicit paths and separate queries:
const usersWithPosts = await prisma.user.findMany({
  include: {
    posts: true
  }
});

// Then fetch comments separately
const postIds = usersWithPosts.flatMap(u => u.posts.map(p => p.id));
const commentsWithAuthors = await prisma.comment.findMany({
  include: {
    author: true
  },
  where: {
    postId: { in: postIds }
  }
});

// Problem: Potential infinite loop
const infiniteLoop = await prisma.user.findMany({
  include: {
    manager: {
      include: {
        manager: { // This could go infinitely deep
          include: {
            manager: true
          }
        }
      }
    }
  }
});

// Solution: Limit depth or use recursive CTEs
const limitedDepth = await prisma.user.findMany({
  include: {
    manager: {
      include: {
        manager: {
          select: {
            id: true,
            name: true
            // Don't include manager again
          }
        }
      }
    }
  }
});

// Complex query that might cause P2016
const complexResult = await prisma.$queryRaw`
  SELECT
    u.id as user_id,
    u.name as user_name,
    p.id as post_id,
    p.title as post_title,
    c.id as comment_id,
    c.content as comment_content,
    ca.name as comment_author_name
  FROM "User" u
  LEFT JOIN "Post" p ON p."userId" = u.id
  LEFT JOIN "Comment" c ON c."postId" = p.id
  LEFT JOIN "User" ca ON c."authorId" = ca.id
  WHERE u.id = ${userId}
  ORDER BY p."createdAt" DESC, c."createdAt" ASC
`;

// This gives you full control over the query structure
// but loses type safety and Prisma's query optimization