What is the best way to check if table exists in DynamoDb?
I would appreciate it if the code would be in PHP.
Either active or not.
* Added later as an example to various cases for error code 400
It's very easy to check if the table exist, it can have one of the following TableStatus => CREATING, ACTIVE, DELETING or UPDATING
but in case i get error 400 it can mean more than one thing.
1) sent null string as a table name by mistake.
[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) syntax error in the command sent to DynamoDB, for example writting tabel_name instead of table_name.
[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) I would guess but didn't check, if I exceed at that same time the provisioned capacity on the table.
GetItem – Retrieves a single item from a table. This is the most efficient way to read a single item because it provides direct access to the physical location of the item. (DynamoDB also provides the BatchGetItem operation, allowing you to perform up to 100 GetItem calls in a single operation.)
In DynamoDB, tables, items, and attributes are the core components that you work with. A table is a collection of items, and each item is a collection of attributes. DynamoDB uses primary keys to uniquely identify each item in a table and secondary indexes to provide more querying flexibility.
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
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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