update

Introduction

update method performs update request using aws-sdk UpdateItemCommand.

execute

update takes 3 arguments:

1. (required) any Condition expression with at least item identifier
2. (required) any Update Expression.
3. (optionnal) options

const res = await User.update(
  {
    id: "user-2",
    sex: "female",
  },
  {
    friendId: {
      $push: "user-1",
    },
    age: {
      $incr: 1,
    },
  },
  { ReturnConsumedCapacity: "TOTAL" }
);

Underlying request

import { DynamoDBClient, UpdateItemCommand } from "@aws-sdk/client-dynamodb";

const client = new DynamoDBClient(config);

const cmd = new UpdateItemCommand({
  TableName: "user-table",
  Key: { id: { S: "user-2" } },
  UpdateExpression: "SET #n0 = list_append(#n0, :v1), #n2 = #n2 + :v3",
  ConditionExpression: "#n4 = :v5",
  ExpressionAttributeNames: { "#n0": "friendId", "#n2": "age", "#n4": "sex" },
  ExpressionAttributeValues: { ":v1": { L: ["user-1"] }, ":v3": { N: "1" }, ":v5": { S: "female" } },
  ReturnConsumedCapacity: "TOTAL",
});

client.send(cmd);

options

options is an object which accepts UpdateItemCommandInput options and DynamoQL specific options.

exec

exec boolean directive to execute or not the actual request.
When false update will return UpdateItemCommandInput object.

import type { UpdateItemCommandInput } from "@aws-sdk/client-dynamodb";

const cmd: UpdateItemCommandInput = await User.update(
  {
    id: "user-2",
    sex: "female",
  },
  {
    friendId: {
      $push: "user-1",
    },
    age: {
      $incr: 1,
    },
  },
  { exec: false }
);