检查 DynamoDB 中是否存在表的最佳方法是什么?

What is the best way to check if table exists in DynamoDB?(检查 DynamoDB 中是否存在表的最佳方法是什么?)

问题描述

检查 DynamoDb 中是否存在表的最佳方法是什么?

What is the best way to check if table exists in DynamoDb?

如果代码在 PHP 中，我将不胜感激.

I would appreciate it if the code would be in PHP.

无论是否活跃.

* 稍后作为示例添加到错误代码 400 的各种情况

* Added later as an example to various cases for error code 400

检查表是否存在很容易，它可以有以下之一TableStatus => 正在创建、活动、删除或更新

It's very easy to check if the table exist, it can have one of the following TableStatus => CREATING, ACTIVE, DELETING or UPDATING

但如果我收到错误 400，它可能意味着不止一件事.

but in case i get error 400 it can mean more than one thing.

1) 错误地将空字符串作为表名发送.

1) sent null string as a table name by mistake.

[x-aws-body] => {"TableName":""})

[x-aws-body] => {"TableName":""} )

[body] => CFSimpleXML Object
    (
        [__type] => com.amazon.coral.validate#ValidationException
        [message] => The paramater 'tableName' must be at least 3 characters long and at most 255 characters long
    )

[status] => 400

2) 发送到 DynamoDB 的命令中存在语法错误，例如写入 table_name 而不是 table_name.

2) syntax error in the command sent to DynamoDB, for example writting tabel_name instead of table_name.

[x-aws-body] => {"TabelName":"test7"})

[x-aws-body] => {"TabelName":"test7"} )

[body] => CFSimpleXML Object
    (
        [__type] => com.amazon.coral.validate#ValidationException
        [message] => The paramater 'tableName' is required but was not present in the request
    )

[status] => 400

3) 我会猜测但没有检查，如果我同时超过了桌子上的预置容量.

3) I would guess but didn't check, if I exceed at that same time the provisioned capacity on the table.

推荐答案

你可以看看官方PHP SDK的describe_table".400 表示不存在" 官方文档中有一个相当广泛的示例.看看它在删除"示例中是如何使用的，就在底部.

You can have a look at "describe_table" of the official PHP SDK. 400 means "does not exist" There is a pretty extensive example in the official documentation. Look at how it is used in the "delete" example, right at the bottom.

http://docs.amazonwebservices.com/amazondynamodb/latest/developerguide/LowLevelPHPTableOperationsExample.html

这是文档中的(剥离的)示例

Here is the (stripped) example from the doc

<?php
require_once dirname(__FILE__) . '/sdk/sdk.class.php';

$dynamodb = new AmazonDynamoDB();
$table_name = 'ExampleTable';
$response = $dynamodb->describe_table(array('TableName' => $table_name));

if((integer) $response->status !== 400)
{
    $error_type = $response->body->__type;
    $error_code = explode('#', $error_type)[1];
    if($error_code == 'ResourceNotFoundException')
    {
        echo "Table ".$table_name." exists.";
    }
}
?>

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