Working with scalar lists

Scalar lists are represented by the [] modifier and are only available if the underlying database supports scalar lists. The following example has one scalar String list named pets:

Relational databases

model User {
  id   Int      @id @default(autoincrement())
  name String
  pets String[]
}

MongoDB

model User {
  id   String   @id @default(auto()) @map("_id") @db.ObjectId
  name String
  pets String[]
}

Example field value:

['Fido', 'Snoopy', 'Brian']

Setting the value of a scalar list

The following example demonstrates how to set the value of a scalar list (coinflips) when you create a model:

const createdUser = await prisma.user.create({
  data: {
    email: 'eloise@prisma.io',
    coinflips: [true, true, true, false, true],
  },
})

Unsetting the value of a scalar list

warning

This method is available on MongoDB only in versions 3.11.1 and later.

The following example demonstrates how to unset the value of a scalar list (coinflips):

const createdUser = await prisma.user.create({
  data: {
    email: 'eloise@prisma.io',
    coinflips: {
      unset: true,
    },
  },
})

Unlike set: null, unset removes the list entirely.

Adding items to a scalar list

warning

Available for:

• PostgreSQL in versions 2.15.0 and later
• CockroachDB in versions 3.9.0 and later
• MongoDB in versions 3.11.0 and later

Use the push method to add a single value to a scalar list:

const userUpdate = await prisma.user.update({
  where: {
    id: 9,
  },
  data: {
    coinflips: {
      push: true,
    },
  },
})

In earlier versions, you have to overwrite the entire value. The following example retrieves user, uses push() to add three new coin flips, and overwrites the coinflips field in an update:

const user = await prisma.user.findUnique({
  where: {
    email: 'eloise@prisma.io',
  },
})

if (user) {
  console.log(user.coinflips)

  user.coinflips.push(true, true, false)

  const updatedUser = await prisma.user.update({
    where: {
      email: 'eloise@prisma.io',
    },
    data: {
      coinflips: user.coinflips,
    },
  })

  console.log(updatedUser.coinflips)
}

Filtering scalar lists

warning

Available for:

• PostgreSQL in versions 2.15.0 and later
• CockroachDB in versions 3.9.0 and later
• MongoDB in versions 3.11.0 and later

Use scalar list filters to filter for records with scalar lists that match a specific condition. The following example returns all posts where the tags list includes databases and typescript:

const posts = await prisma.post.findMany({
  where: {
    tags: {
      hasEvery: ['databases', 'typescript'],
    },
  },
})

NULL values in arrays

warning

This section applies to:

• PostgreSQL in versions 2.15.0 and later
• CockroachDB in versions 3.9.0 and later

When using scalar list filters with a relational database connector, array fields with a NULL value are not considered by the following conditions:

• NOT (array does not contain X)
• isEmpty (array is empty)

This means that records you might expect to see are not returned. Consider the following examples:

• The following query returns all posts where the tags do not include databases:

  const posts = await prisma.post.findMany({
    where: {
      NOT: {
        tags: {
          has: 'databases',
        },
      },
    },
  })
  • ✔ Arrays that do not contain "databases", such as {"typescript", "graphql"}
  • ✔ Empty arrays, such as []

  The query does not return:

  • ✘ NULL arrays, even though they do not contain "databases"

The following query returns all posts where tags is empty:

const posts = await prisma.post.findMany({
  where: {
    tags: {
      isEmpty: true,
    },
  },
})

The query returns:

• ✔ Empty arrays, such as []

The query does not return:

• ✘ NULL arrays, even though they could be considered empty

To work around this issue, you can set the default value of array fields to [].