如何使用UpdateItem更改数值

var AWS = require("aws-sdk");

AWS.config.update({
  region: "us-west-2",
  endpoint: "http://localhost:8000"
});

var docClient = new AWS.DynamoDB.DocumentClient();

var params = {
    TableName: "YourTableName",
    Key: {
        "KeyAttribute": "YourKey"
    },
    UpdateExpression: "set NumberAttribute = :n",
    ExpressionAttributeValues: {
        ":n": 100 // 新的数值
    },
    ReturnValues: "UPDATED_NEW"
};

docClient.update(params, function(err, data) {
    if (err) {
        console.error("Unable to update item. Error JSON:", JSON.stringify(err, null, 2));
    } else {
        console.log("UpdateItem succeeded:", JSON.stringify(data, null, 2));
    }
});