1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
|
.. service:: DynamoDb 2011-12-05
Creating tables
---------------
You must first create a table that can be used to store items. Even though Amazon DynamoDB tables do not use a fixed
schema, you do need to create a schema for the table's keys. This is explained in greater detail in Amazon DynamoDB's
`Data Model documentation <http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/DataModel.html>`_. You
will also need to specify the amount of `provisioned throughput
<http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/ProvisionedThroughputIntro.html>`_ that should
be made available to the table.
.. example:: DynamoDb/Integration/DynamoDb_20111205_Test.php testCreateTable
The table will now have a status of ``CREATING`` while the table is being provisioned. You can use a waiter to poll the
table until it becomes ``ACTIVE``.
.. example:: DynamoDb/Integration/DynamoDb_20111205_Test.php testWaitUntilTableExists
A full list of the parameters available to the ``createTable()`` operation can be found in the
`API documentation <http://docs.aws.amazon.com/aws-sdk-php/latest/class-Aws.DynamoDb.DynamoDbClient.html#_createTable>`_.
Updating a table
----------------
You can also update the table after it's been created using the `updateTable() <http://docs.aws.amazon.com/aws-sdk-php/latest/class-Aws.DynamoDb.DynamoDbClient.html#_updateTable>`_ method. This allows you to do things
like increase or decrease your provisioned throughput capacity.
.. example:: DynamoDb/Integration/DynamoDb_20111205_Test.php testUpdateTable
Describing a table
------------------
Now that the table is created, you can use the
`describeTable() <http://docs.aws.amazon.com/aws-sdk-php/latest/class-Aws.DynamoDb.DynamoDbClient.html#_describeTable>`_
method to get information about the table.
.. example:: DynamoDb/Integration/DynamoDb_20111205_Test.php testDescribeTable
The return value of the ``describeTable()`` method is a ``Guzzle\Service\Resource\Model`` object that can be used like
an array. For example, you could retrieve the number of items in a table or the amount of provisioned read throughput.
Listing tables
--------------
You can retrieve a list of all of the tables associated with a specific endpoint using the
`listTables() <http://docs.aws.amazon.com/aws-sdk-php/latest/class-Aws.DynamoDb.DynamoDbClient.html#_listTables>`_
method. Each Amazon DynamoDB endpoint is entirely independent. For example, if you have two tables called "MyTable," one
in US-EAST-1 and one in US-WEST-2, they are completely independent and do not share any data. The ListTables operation
returns all of the table names associated with the account making the request, for the endpoint that receives the
request.
.. example:: DynamoDb/Integration/DynamoDb_20111205_Test.php testListTables
Iterating over all tables
~~~~~~~~~~~~~~~~~~~~~~~~~
The result of a ``listTables()`` operation might be truncated. Because of this, it is usually better to use an iterator
to retrieve a complete list of all of the tables owned by your account in a specific region. The iterator will
automatically handle sending any necessary subsequent requests.
.. example:: DynamoDb/Integration/DynamoDb_20111205_Test.php testListTablesWithIterator
.. tip::
You can convert an iterator to an array using the ``toArray()`` method of the iterator.
Adding items
------------
You can add an item to our *errors* table using the
`putItem() <http://docs.aws.amazon.com/aws-sdk-php/latest/class-Aws.DynamoDb.DynamoDbClient.html#_putItem>`_
method of the client.
.. example:: DynamoDb/Integration/DynamoDb_20111205_Test.php testAddItem
As you can see, the ``formatAttributes()`` method of the client can be used to more easily format the attributes of the
item. Alternatively, you can provide the item attributes without using the helper method:
.. example:: DynamoDb/Integration/DynamoDb_20111205_Test.php testAddItemWithoutHelperMethod
Retrieving items
----------------
You can check if the item was added correctly using the
`getItem() <http://docs.aws.amazon.com/aws-sdk-php/latest/class-Aws.DynamoDb.DynamoDbClient.html#_getItem>`_
method of the client. Because Amazon DynamoDB works under an 'eventual consistency' model, we need to specify that we
are performing a `consistent read
<http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/APISummary.html#DataReadConsistency>`_ operation.
.. example:: DynamoDb/Integration/DynamoDb_20111205_Test.php testGetItem
You can also retrieve items in batches of up to 100 using the `BatchGetItem()
<http://docs.aws.amazon.com/aws-sdk-php/latest/class-Aws.DynamoDb.DynamoDbClient.html#_batchGetItem>`_ method.
.. example:: DynamoDb/Integration/DynamoDb_20111205_Test.php testBatchGetItem
Query and scan
--------------
Once data is in an Amazon DynamoDB table, you have two APIs for searching the data:
`Query and Scan <http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/QueryAndScan.html>`_.
Query
~~~~~
A query operation searches only primary key attribute values and supports a subset of comparison operators on key
attribute values to refine the search process. A query returns all of the item data for the matching primary keys
(all of each item's attributes) up to 1MB of data per query operation.
Let's say we want a list of all "1201" errors that occurred in the last 15 minutes. We could issue a single query
that will search by the primary key of the table and retrieve up to 1MB of the items. However, a better approach is to
use the query iterator to retrieve the entire list of all items matching the query.
.. example:: DynamoDb/Integration/DynamoDb_20111205_Test.php testQuery
Scan
~~~~
A scan operation scans the entire table. You can specify filters to apply to the results to refine the values
returned to you, after the complete scan. Amazon DynamoDB puts a 1MB limit on the scan (the limit applies before
the results are filtered).
A scan can be useful for more complex searches. For example, we can retrieve all of the errors in the last 15
minutes that contain the word "overflow":
.. example:: DynamoDb/Integration/DynamoDb_20111205_Test.php testScan
Deleting a table
----------------
.. warning::
Deleting a table will also permanently delete all of its contents.
Now that you've taken a quick tour of the PHP client for Amazon DynamoDB, you will want to clean up by deleting the
resources you created.
.. example:: DynamoDb/Integration/DynamoDb_20111205_Test.php testDeleteTable
Using the WriteRequestBatch
---------------------------
You can use the ``WriteRequestBatch`` if you need to write or delete many items as quickly as possible. The
WriteRequestBatch provides a high level of performance because it converts what would normally be a separate HTTP
request for each operation into HTTP requests containing up to 25 comparable requests per transaction.
If you have a large array of items you wish to add to your table, you could iterate over the them, add each item to the
batch object. After all the items are added call ``flush()``. The batch object will automatically flush the batch and
write items to Amazon DynamoDB after hitting a customizable threshold. A final call to the batch object's ``flush()``
method is necessary to transfer any remaining items in the queue.
.. example:: DynamoDb/Integration/WriteRequestBatch_20111205_Test.php testWriteRequestBatchForPuts
You can also use the ``WriteRequestBatch`` object to delete items in batches.
.. example:: DynamoDb/Integration/WriteRequestBatch_20111205_Test.php testWriteRequestBatchForDeletes
The ``WriteRequestBatch``, ``PutRequest``, and ``DeleteRequest`` classes are all a part of the
``Aws\DynamoDb\Model\BatchRequest`` namespace.
.. apiref:: DynamoDb 2011-12-05
|
