data-prefer-select-over-include.md

---

title: Prefer Select Over Include in Prisma Queries impact: HIGH impactDescription: Reduces data transfer and prevents data leaks tags: prisma, database, performance, security

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Prefer Select Over Include in Prisma Queries

Impact: HIGH

Using select instead of include fetches only the fields you need. This improves performance and prevents accidental exposure of sensitive data.

Incorrect (include fetches all fields):

const item = await this.prisma.item.findFirst({
  where: { slug },
  include: {
    seller: true,  // Gets ALL seller fields including internal ones
    reviews: true, // Gets ALL review fields
  }
});

Correct (select for specific fields):

const item = await this.prisma.$replica().item.findFirst({
  where: { slug, status: 'PUBLISHED' },
  select: {
    id: true,
    title: true,
    slug: true,
    description: true,
    price: true,
    imageUrl: true,
    seller: {
      select: {
        id: true,
        name: true,
        logoUrl: true,
        rating: true,
      }
    },
    reviews: {
      select: {
        id: true,
        rating: true,
        comment: true,
        createdAt: true,
        user: {
          select: {
            id: true,
            name: true,
          }
        }
      },
      take: 10,
      orderBy: { createdAt: 'desc' },
    }
  }
});

Benefits:

• Performance: Smaller payloads, faster queries
• Security: Prevents accidental exposure of sensitive fields
• Clarity: Makes data requirements explicit
• Network: Less data transferred between DB and backend

Exception: Use include only when you genuinely need ALL fields from a relation, which is rare. Always prefer select.