Export Data Store Entity to CSV Smart Service

Overview

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

It can be used to export data from Appian that can then be imported into other third-party applications. A developer 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:

• Assignment Options: This smart service can be either attended or unattended (default).

Configuration options

Data tab

Node inputs

Node outputs

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 )

Parameters

Returns

Document

Example

Copy and paste an example into an Appian Expression Editor to experiment with it.

Replace the ENTITY and FOLDER with the appropriate constants for your application.

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a!localVariables(
  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 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
      )
    )
  }
)

Usage considerations

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.
• 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.

Related objects

Data Types:

• Selection
• Aggregation
• Query Filter
• Logical Expression

Feature compatibility

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