I have an IDB with the following structure :

id: 1
name: "test"
operations: [
  {
    column: "active"
    operator: "="
    value: true
  }
]

Here the ID is added like so :

request.onupgradeneeded = e => {
            let db = e.target.result
            db.createObjectStore('filters', { autoIncrement : true, keyPath: 'id'})
        }

Users can either add a new record, in which case it will have id: 2 and so on, or add an operation to an existing record.

What should I do to add an auto incrementing key to each operations ?

Expected result :

id: 1
name: "test"
operations: [
  {
    id: 1
    column: "active"
    operator: "="
    value: true
  },
  {
    id: 2
    column: "age"
    operator: ">"
    value: 32
  },
]