如需與 Amazon Timestream for LiveAnalytics 類似的功能，請考慮使用 Amazon Timestream for InfluxDB。它提供簡化的資料擷取和單一位數毫秒查詢回應時間，以進行即時分析。[在這裡](https://docs.aws.amazon.com//timestream/latest/developerguide/timestream-for-influxdb.html)進一步了解。

本文為英文版的機器翻譯版本，如內容有任何歧義或不一致之處，概以英文版為準。

# 列出資料庫
<a name="code-samples.list-db"></a>

您可以使用下列程式碼片段來列出資料庫。

**注意**  
這些程式碼片段是以 [GitHub](https://github.com/awslabs/amazon-timestream-tools/blob/master/sample_apps) 上的完整範例應用程式為基礎。如需如何開始使用範例應用程式的詳細資訊，請參閱[範例應用程式](sample-apps.md)。

------
#### [  Java  ]

```
    public void listDatabases() {
        System.out.println("Listing databases");
        ListDatabasesRequest request = new ListDatabasesRequest();
        ListDatabasesResult result = amazonTimestreamWrite.listDatabases(request);
        final List<Database> databases = result.getDatabases();
        printDatabases(databases);

        String nextToken = result.getNextToken();
        while (nextToken != null && !nextToken.isEmpty()) {
            request.setNextToken(nextToken);
            ListDatabasesResult nextResult = amazonTimestreamWrite.listDatabases(request);
            final List<Database> nextDatabases = nextResult.getDatabases();
            printDatabases(nextDatabases);
            nextToken = nextResult.getNextToken();
        }
    }
    
    private void printDatabases(List<Database> databases) {
        for (Database db : databases) {
            System.out.println(db.getDatabaseName());
        }
    }
```

------
#### [  Java v2  ]

```
    public void listDatabases() {
        System.out.println("Listing databases");
        ListDatabasesRequest request = ListDatabasesRequest.builder().maxResults(2).build();
        ListDatabasesIterable listDatabasesIterable = timestreamWriteClient.listDatabasesPaginator(request);
        for(ListDatabasesResponse listDatabasesResponse : listDatabasesIterable) {
            final List<Database> databases = listDatabasesResponse.databases();
            databases.forEach(database -> System.out.println(database.databaseName()));
        }
    }
```

------
#### [  Go  ]

```
// List databases.
    listDatabasesMaxResult := int64(15)

    listDatabasesInput := &timestreamwrite.ListDatabasesInput{
        MaxResults: &listDatabasesMaxResult,
    }

    listDatabasesOutput, err := writeSvc.ListDatabases(listDatabasesInput)

    if err != nil {
        fmt.Println("Error:")
        fmt.Println(err)
    } else {
        fmt.Println("List databases is successful, below is the output:")
        fmt.Println(listDatabasesOutput)
    }
```

------
#### [  Python  ]

```
    def list_databases(self):
        print("Listing databases")
        try:
            result = self.client.list_databases(MaxResults=5)
            self._print_databases(result['Databases'])
            next_token = result.get('NextToken', None)
            while next_token:
                result = self.client.list_databases(NextToken=next_token, MaxResults=5)
                self._print_databases(result['Databases'])
                next_token = result.get('NextToken', None)
        except Exception as err:
            print("List databases failed:", err)
```

------
#### [  Node.js  ]

下列程式碼片段使用適用於 JavaScript v3 的 AWS SDK。如需如何安裝用戶端和用量的詳細資訊，請參閱 [Timestream Write Client - AWS SDK for JavaScript v3](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/clients/client-timestream-write/index.html)。

另請參閱[類別 ListDatabasesCommand](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/clients/client-timestream-write/classes/listdatabasescommand.html) 和 [ListDatabases](https://docs.aws.amazon.com/timestream/latest/developerguide/API_ListDatabases.html)。

```
import { TimestreamWriteClient, ListDatabasesCommand } from "@aws-sdk/client-timestream-write";
const writeClient = new TimestreamWriteClient({ region: "us-east-1" });

const params = {
    MaxResults: 15
};

const command = new ListDatabasesCommand(params);

getDatabasesList(null);

async function getDatabasesList(nextToken) {
    if (nextToken) {
        params.NextToken = nextToken;
    }

    try {
        const data = await writeClient.send(command);

        data.Databases.forEach(function (database) {
            console.log(database.DatabaseName);
        });

        if (data.NextToken) {
            return getDatabasesList(data.NextToken);
        }
    } catch (error) {
        console.log("Error while listing databases", error);
    }
}
```

下列程式碼片段使用適用於 JavaScript V2 樣式的 AWS SDK。它以 [Node.js 範例應用程式為基礎，Amazon Timestream for LiveAnalytics 應用程式為 GitHub](https://github.com/awslabs/amazon-timestream-tools/tree/mainline/sample_apps/js)。

```
async function listDatabases() {
    console.log("Listing databases:");
    const databases = await getDatabasesList(null);
    databases.forEach(function(database){
        console.log(database.DatabaseName);
    });
}

function getDatabasesList(nextToken, databases = []) {
    var params = {
        MaxResults: 15
    };

    if(nextToken) {
        params.NextToken = nextToken;
    }

    return writeClient.listDatabases(params).promise()
        .then(
            (data) => {
                databases.push.apply(databases, data.Databases);
                if (data.NextToken) {
                    return getDatabasesList(data.NextToken, databases);
                } else {
                    return databases;
                }
            },
            (err) => {
                console.log("Error while listing databases", err);
            });
}
```

------
#### [  .NET  ]

```
        public async Task ListDatabases()
        {
            Console.WriteLine("Listing Databases");

            try
            {
                var listDatabasesRequest = new ListDatabasesRequest
                {
                    MaxResults = 5
                };
                ListDatabasesResponse response = await writeClient.ListDatabasesAsync(listDatabasesRequest);
                PrintDatabases(response.Databases);
                var nextToken = response.NextToken;
                while (nextToken != null)
                {
                    listDatabasesRequest.NextToken = nextToken;
                    response = await writeClient.ListDatabasesAsync(listDatabasesRequest);
                    PrintDatabases(response.Databases);
                    nextToken = response.NextToken;
                }
            }
            catch (Exception e)
            {
                Console.WriteLine("List database failed:" + e.ToString());
            }

        }
```

------