AWS SDK DynamoDB 客户端和 DocumentClient 之间的区别?

Difference between AWS SDK DynamoDB client and DocumentClient?(AWS SDK DynamoDB 客户端和 DocumentClient 之间的区别?)

问题描述

我想知道 AWS SDK DynamoDB 客户端和 DynamoDB DocumentClient 之间的区别?在哪个用例中我们应该使用 DynamoDB 客户端而不是 DocumentClient?

I want to know the difference between the AWS SDK DynamoDB client and the DynamoDB DocumentClient? In which use case should we use the DynamoDB client over the DocumentClient?

const dynamoClient = new AWS.DynamoDB.DocumentClient();

vs 

const dynamo = new AWS.DynamoDB();

推荐答案

我认为最好通过比较两个执行相同操作的代码示例来回答这个问题.

I think this can be best answered by comparing two code samples which do the same thing.

以下是使用 dynamoDB 客户端放置项目的方法:

Here's how you put an item using the dynamoDB client:

var params = {
    Item: {
        "AlbumTitle": {
            S: "Somewhat Famous"
        },
        "Artist": {
            S: "No One You Know"
        },
        "SongTitle": {
            S: "Call Me Today"
        }
    },
    TableName: "Music"
};
dynamodb.putItem(params, function (err, data) {
    if (err) console.log(err)
    else console.log(data);           
});

以下是使用 DocumentClient API 放置相同项目的方法:

Here's how you put the same item using the DocumentClient API:

var params = {
    Item: {
        "AlbumTitle": "Somewhat Famous",
        "Artist": "No One You Know",
        "SongTitle": "Call Me Today"
    },
    TableName: "Music"
};

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

documentClient.put(params, function (err, data) {
    if (err) console.log(err);
    else console.log(data);
});

正如您在 DocumentClient 中看到的那样，Item 以更自然的方式指定.更新 DDB 的所有其他操作(update()、delete())和从读取操作返回的项目(get()，<代码>查询()，<代码>扫描()).