Amazon SimpleDB - Query

Declaration

<AMAWSSIMPLEDB ACCESSKEY="text" SECRETKEY="text (encrypted)" 
USERAGENT="text" MAXERRORRETRY="number" SERVICEURL="text" 
PROXYHOST="text" PROXYPORT="number" PROXYUSER="text" 
PROXYPWD="text (encrypted)" SIGNMETHOD="text" 
SIGNVERSION="number" QUERY="text (query expression)" 
RESULTDATASET="text" NEXTTOKEN="text" RESULTVARIABLE="text" 
CONSISTENTREAD="yes/no" />

Description: Returns a set of attributes for item names that match the Select expression. Select is similar to the standard SQL Query SELECT statement. Results are populated into a dataset.

IMPORTANT: SimpleDB activities use Amazon's SimpleDB engine to perform their work, therefore, launching and operating Amazon SimpleDB requires a valid Access Key ID and Secret Access Key.

Practical Usage

Used to query items within SimpleDB.

Connection Parameters

Property

Type

Required

Default

Markup

Description

Connection

 

 

 

 

Indicates where AWS user credentials and preferences should originate from. This is a design mode parameter used only during task construction and configuration, thus, comprises no markup. The available options are:

  • Host (default) - Specifies that user credentials and/or advanced preferences are configured individually for this activity. This option is normally chosen if only a single activity is required to complete an operation.

  • Session - Specifies that user credentials and/or advanced preferences are obtained from a pre-configured session created in an earlier step with the use of the SimpelDB - Create session activity. This option is normally chosen if a combination of related activities are required to complete an operation. Linking several activities to a single session eliminates redundancy. Additionally, a single task supports construction and simultaneous execution of multiple sessions, improving efficiency.

Session

Text

Yes if connection is session-based

SQSSession1

SESSION="SimpleDBSession1"

The name of an existing session to attach this activity to. This parameter is active only if the Connection parameter is set to Session. The default session name is 'SimpleDBSession1'.

Access key

Text

Yes if connection is host-based

(Empty)

ACCESSKEY=

"022QF06E7MXBSH9DHM02"

A 20-character alphanumeric string that uniquely identifies the owner of the AWS service account, similar to a username. This key along with a corresponding secret access key forms a secure information set that AWS uses to confirm a valid user's identity. This parameter is active only if the Connection parameter is set to Host.

Secret Access key

Text

Yes if connection is host-based

(Empty)

SECRETKEY=

"kWcrlUX5JEDGM/LtmEENI/

aVmYvHNif5zB+d9+ct"

A 40-character string that serves the role as password to access the AWS service account. This along with an associated access key forms a secure information set that SQS uses to confirm a valid user's identity. This parameter is active only if the Connection parameter is set to Host.

User agent

Text

No

AutoMate

USERAGENT="AutoMate"

The name of the client or application initiating requests to AWS, which in this case, is AutoMate. This parameter's default value is 'AutoMate'. 

Service URL

Text

No

(Empty)

SERVICEURL=

"https://sdb.eu-west-1.amazonaws.com"

The URL that provides the service endpoint. To make the service call to a different region, you can pass the region-specific endpoint URL. For example, entering  https://sdb.us-west-1.amazonaws.com points to US West (Northern California) region. A complete list of SQS regions, along with their associated endpoints and valid protocols can be found below under SimpleDB Endpoints and Regions.

Maximum retry on error

Number

No

(Empty)

MAXERRORRETRY="4"

The total amount of times this activity should retry its request to the server before returning an error. Network components can generate errors anytime in the life of a request, thus, implementing retries can increase reliability. 

Proxy host

Text

No

(Empty)

PROXYHOST="proxy.host.com"

The host name (e.g., server.domain.com) or IP address (e.g., xxx.xxx.xxx.xxx) of the proxy server to use when connecting to AWS.  

Proxy port

Number

No

(Empty)

PROXYPORT="1028"

The port that should be used to connect to the proxy server.

Proxy username

Text

No

(Empty)

PROXYUSER="username"

The username that should be used to authenticate connection with the proxy server (if required).

Proxy password

Text

No

(Empty)

PROXYPWD="encrypted"

The password that should be used to authenticate connection with the proxy server (if required).

Signature method

Text

No

(Empty)

SIGNMETHOD="HmacSHA256"

The signature method to use for signing the request. This provides a valid hashing algorithm for signature calculation. Acceptable AWS signature methods are HmacSHA1 and HmacSHA256.

Signature version

Number

No

(Empty)

SIGNVERSION="2"

The signature version for signing the request. Valid AWS signature versions are 2 and 4. The difference with version 4 is that it allows you to sign your message using a key that is derived from your secret access key rather than using the secret access key itself.

Data Parameters

Property

Type

Required

Default

Markup

Description

Query

Text

Yes

(Empty)

QUERY="select * from myDomain"

The expression used to query the domain.

Next Token (optional)

Number

No

(Empty)

NEXTTOKEN="2"

String that tells Amazon SimpleDB where to start the next list of item names.

Populate variable with returned next token

Text

No

(Empty)

RESULTVARIABLE="var1"

The name of the variable in which to populate with the next token.

Consistent read

Yes/No

No

No

CONSISTENTREAD="yes"

If set to YES, ensures that the most recent data is returned. Set to NO by default.

Create and populate dataset with query result

Text

Yes

(Empty)

RESULTDATASET="mydataset"

The name of the dataset in which to create and populate with the query result. More details about the specific fields this dataset creates can be found below under Datasets.

Description tab - A custom description can be provided on the Description tab to convey additional information or share special notes about a task step.

Error Causes tab - Specify how this step should behave upon the occurrence of an error. (Refer to Task Builder > Error Causes Tab for details.)

On Error tab - Specify what AWE should do if this step encounters an error as defined on the Error Causes tab. (Refer to Task Builder > On Error Tab for details.)

SimpleDB Endpoints and Regions

For a complete list of Amazon Service endpoints, refer to the AWS documentation at https://docs.aws.amazon.com/general/latest/gr/rande.html.

Datasets

A dataset is a multiple column, multiple row container object. This activity creates and populates a dataset containing a specific set of fields in addition to the standard dataset fields. The table below describes these fields (assuming the dataset name assigned was theDataset).

Name

Type

Return Value

theDataset.ItemName

Text

Returns the item name.

theDataset.Attributes

Text

Returns the item's attributes.

Example

The sample AML code below can be copied and pasted directly into the Steps panel of the Task Builder.

Description: Execute SimpleDB query : "select * from theData". Create and populate dataset "theDataset" with query result. Use default SimpleDB session.

<AMAWSSIMPLEDB QUERY="select * from theData" RESULTDATASET="theDataset" />