How to increment the number in map by add

[Derek-X-Wang]

Hi @tywalch,

Is there any way to increment the number inside of a map object?

For example

export const UserEntity = new Entity(
  {
    model: {
      version: "1",
      entity: "User",
      service: "Demo",
    },
    attributes: {
      userId: {
        type: "string",
        required: true,
      },
      statistics: {
        type: "map",
        properties: {
          storeCount: {
            type: "number",
          },
          orderCount: {
            type: "number",
          },
        },
      },
      createdAt: {
        type: "number",
        default: () => Date.now(),
        // cannot be modified after created
        readOnly: true
      },
      updatedAt: {
        type: "number",
        // watch for changes to any attribute
        watch: "*",
        // set current timestamp when updated
        set: () => Date.now(),
        readOnly: true
      }
    },
    indexes: {
      user: {
        collection: "user",
        pk: {
          field: "pk",
          composite: ["userId"],
        },
        sk: {
          field: "sk",
          composite: [],
        },
      },
    },
  },
  Dynamo.Configuration
);

and I want to increment storeCount in statistics map object

await UserEntity.update({
    userId,
  })
    .add({
      "statistics.storeCount": by, // something like this. not sure if electrodb has this feature.
    })
    .go();

[tywalch]

You can use the .data() method for this:

UserEntity.update({ userId })
  .data((attr, op) => {
    op.add(attr.statistics.storeCount, 1)
  })
  .go();

Full example in playground

[Derek-X-Wang]

Thank you so much!