Export Data Store Entity to CSV Smart Service

This is the new Export to CSV Smart Service. If you need to export to Excel, use the Export to Excel Smart Service.

Summary

The Export Data Store Entity to CSV Smart Service allows designers to safely export large datasets.

It can be used to export data from Appian that can then be imported into other third-party applications. A designer may want to export all data or just updates made within the last day.

The Smart Service returns a document in a CSV format.

Properties

  • Category: Document Generation
  • Icon: alt text
  • Assignment Options: This smart service can be either attended or unattended (default).

Node Inputs

Name Data Type Description Required Multiple
Data Store Entity Data Store Entity The data store entity to query. Yes No
Selection Selection A list of fields to retrieve, created with a!querySelection(). No No
Aggregation Aggregation A list of fields and the operations to perform on them when retrieving the data, created with a!queryAggregation(). No No
Filters Any Type A set of conditions to apply to the queried data before any grouping or aggregation. Can use either a list of a!queryFilter() or a single a!queryLogicalExpression(). When using a list of a!queryFilter(), all filters are combined using the AND operator. No Yes
New Document Name Text The name of the new document created. No No
New Document Description Text A brief description of the document. No No
Save in Folder Folder The folder to store the new document in. Required when creating a new document. No No
Document to Update Document The document to be updated as a result of the export operation. This can be useful when using the smart service multiple times in the same process model. New contents will be appended at the end of the file. No No
Include Header Boolean Outputs the field name in the first row of the document if set to true. Default: true No No
CSV Delimiter Text The field delimiter used to separate fields in the CSV file. Valid values are: "TAB", "COMMA", "SEMICOLON", "SPACE", "PIPE", "CARET". Default: "COMMA". No No

Node Outputs

Name Data Type Description
New Document Document The document generated as a result of executing this smart service.

a!exportDataStoreEntityToCsv()

Exports the selected data store entity to CSV. This function will only execute inside a saveInto or a Web API.

Syntax

a!exportDataStoreEntityToCsv( entity, selection, aggregation, filters, documentName, documentDescription, saveInFolder, documentToUpdate, includeHeader, csvDelimiter, onSuccess, onError)

  • entity (Data Store Entity): The data store entity to query.
  • selection (Selection): (Optional) A list of fields to retrieve, created with a!querySelection().
  • aggregation (Aggregation): (Optional) A list of fields and the operations to perform on them when retrieving the data, created with a!queryAggregation().
  • filters (Any Type): (Optional) A set of conditions to apply to the queried data before any grouping or aggregation. Can use either a list of a!queryFilter() or a single a!queryLogicalExpression(). When using a list of a!queryFilter(), all filters are combined using the AND operator.
  • documentName (Text): The name of the new document that is to be created by this smart service.
  • documentDescription (Text): (Optional) A brief description of the document.
  • saveInFolder (Folder): The folder where the newly created document is to be stored. Applicable and required when creating a new document.
  • documentToUpdate (Document): The existing document to update with the exported data. Using this parameter will append new contents at the end of the file. Note: A new version of this document will be created.
  • includeHeader (Boolean): (Optional) Outputs the field's label in the first row of the document if set to true. Default: true
  • csvDelimiter (Text): (Optional) The field delimiter used to separate fields in the CSV file. Valid values are: "TAB", "COMMA", "SEMICOLON", "SPACE", "PIPE", "CARET". Default: "COMMA".
  • onSuccess (Any Type): A list of saves or an HTTP response to execute after the smart service executes successfully. Created with a!save() or a!httpResponse(). The document ID of the created/updated document is returned in the fv!newDocument function variable.
  • onError (Any Type): A list of saves or an HTTP response to execute when the smart service does not execute successfully. Created with a!save() or a!httpResponse().

Returns

Document

Example

Copy and paste an example into the INTERFACE DEFINITION in EXPRESSION MODE to see how this works. Replace the ENTITY and FOLDER with the appropriate constants for your application.

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load(
  local!exportDocId,
  local!errorMessage,
  {
    if(
      isnull(
        local!exportDocId
      ),
      /*This link field contains the link that starts the export*/
      a!linkField(
        labelPosition: "COLLAPSED",
        links: a!dynamicLink(
          label: "Export to CSV File",
          saveInto: {
            a!exportDataStoreEntityToCsv(
              entity: cons!ENTITY,
              documentName: "CSV Export " & now(),
              saveInFolder: cons!FOLDER,
              onSuccess: a!save(
                local!exportDocId,
                fv!newDocument
              ),
              /*This displays an error if there is an issue executing the the save*/
              onError: a!save(
                local!errorMessage,
                "Error Exporting File to CSV"
              )
            )
          }
        )
      ),
      {}
    ),
    if(
      /*This only displays the download link if a valid document was created*/
      not(
        isnull(
          local!exportDocId
        )
      ),
      /*This changes the link to a download link for the newly created document */
      a!linkField(
        links: a!documentDownloadLink(
          label: "Download CSV File",
          document: local!exportDocId
        )
      ),
      a!textField(
        value: local!errorMessage,
        readOnly: true
      )
    )
  }
)

Additional Details

The following configurations and expected behavior apply when using the Export Data Store Entity to CSV smart service from the process modeler:

  • To export fields in a specific order, make sure to specify the Selection parameter. Otherwise, the order of the exported fields will not be guaranteed.
  • You may specify either the Selection parameter or the Aggregation parameter but not both. If you do not specify either parameter, all fields are returned.
  • You may specify either a LogicalExpression or a list of Filters in the Filters parameter but not both. If you wish to specify only one condition, specify a Filter. If you wish to specify more than one condition, use LogicalExpression or use a list of Filters.
  • When using fields of type Date or Date and Time in a filter and the filter's value uses either the todate(), now() or today() functions, make sure to cast their value using the appropriate type. For example: cast('type!{http://www.appian.com/ae/types/2009}Date', today()), or cast('type!{http://www.appian.com/ae/types/2009}Datetime', now())

  • To create a CSV file with data from different data store entities, use multiple nodes of this smart service. You can use the Document to Update when exporting a second data store entity.

Avoiding Query Timeouts when Exporting Data

Exporting data store entities from either record lists or smart services relies on sorting the entity by its primary key. This sorting ensures that data is exported consistently - that is, all rows are exported and no row is exported more than once.

Appian export operations use small batches to control the amount of memory consumed. The last row of a batch is tracked and used to determine where the next batch starts. By managing load this way, we avoid high memory consumption when exporting entities with a very large number of rows.

Designers should adhere to Database Performance Best Practices when creating their schema relationships. Because database views do not have a primary key, or the ability to have indexes, Appian recommends exporting data only from tables or materialized views in order to avoid query timeouts with large data sets.

Data Types:

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