title: How to upsert with arrays?
body: <p>Maybe it's a really dumb question, but how should I push a value to an array field when upserting? I tried to search for it but couldn't find this in their documentation.</p>
  <p>This is my schema:</p>
  <pre><code>model Chat {
    id                Int         @default(autoincrement()) @id
    type              Service[]
    chatId            String      @unique
  }
  </code></pre>
  <p>And this is the code I'm trying to use to update the array to push an item to it:</p>
  <pre><code>const chatDb = await prisma.chat.upsert({
        where: {
          chatId: String(ctx.chat.id),
        },
        create: {
          chatId: String(ctx.chat.id),
          type: { set: ['GRAYSCALE'] },
        },
        update: {
          type: { set: ['GRAYSCALE'] },
        },
      });
  </code></pre>
  <p>How I am using right now, I'm substituting the <code>type</code> array for the <code>['GRAYSCALE']</code> array. I want to push the <code>GRAYSCALE</code> item to the array, and not substitute it.</p>
  <p>How should I proceed?</p>