Delete Records Smart Service

Overview

The Delete Records smart service is a powerful tool that allows you to easily delete data from the source system and then automatically sync the changes in Appian. The service lets you delete one or more records at a time per node.

To use this smart service, the record type you want to affect must meet the following conditions:

• The record type uses a database as its source.
• The record type has data sync enabled.

Records can only be deleted from one record type at a time. To delete a record and its related records, you must delete records in the base record type and related record types in separate Delete Records nodes.

Permissions needed

The user executing this activity must have Viewer permissions for the selected record type in order to delete information. If the user does not, the node will fail and pause the process with an exception.

Properties

• Category: Data Services

• Icon:

• Assignment Options: Automated activity

Configuration options

This section contains configuration details specific to this smart service. For more information about common configurations, see the Process Node Properties page.

Data tab

Node inputs

See also: Record Type

Node outputs

Usage considerations

Pass record data to process models

Appian can automatically generate a Delete record action. The generated design objects use the Delete Records smart service in the workflow powering the new action. The generated interface has a rule input called record that uses the record type as its data type. The data needed to identify the record being deleted is seamlessly passed from the interface to the process model. See Delete a record using a process model for an example.

You can also use the record type constructor syntax when deleting records. In the constructor, include the primary key field to identify the record you want to delete. For example, if you have a Customer record type and want to delete the customer with the ID of 72, the data passed to the process model would look similar to the following example.

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{
  recordType!Customer(
    recordType!Customer.fields.customerId: 72
  )
}

Hard and soft deletes

The Delete Records smart service permanently removes data from the source (that is, it performs a hard deletion). If your app or database design requires data to be soft deleted for auditing or to maintain referential integrity, you can use the Write Records smart service to mark a record as deleted according to your schema. For example, your data source may have a field like isDeleted or deletedTime. You could configure a source filter so rows that are marked as deleted are no longer synced in Appian.

Delete related records

The Delete Records smart service does not support deleting from related record types through the base record type. Instead, you must delete related records and the base record in separate Delete Records nodes. For example, you may have a Customer record type that has a one-to-many relationship with a Payment Type record type storing credit card data. If you delete a customer record, you also want to delete any payment data associated with the customer. A process model of this workflow would look similar to the following example:

a!deleteRecords()

The Delete Records smart service is available as an expression function that can be executed inside a saveInto on a Interface Component or as part of a Web API. When creating a web API, select the Delete Records template to generate the object with this function automatically configured.

Syntax

a!deleteRecords( records, onSuccess, onError )

Parameters

Automatic refresh on record views

When you use this smart service on a record view, the view will automatically refresh with the latest record data.

This means that when your record view interface has a Record Action component that triggers the Delete Records smart service, or a button component that triggers the a!deleteRecords() function, the record view data will automatically refresh after the delete occurs.

This refresh behavior only applies to data supplied by rv!record. If your record view definition uses rv!identifier or a local variable to supply the record data, the data will not automatically refresh; instead, you will need to configure additional refresh behavior.

Possible errors

This section explains some of the common reasons the Delete Records smart service might fail.

Configuration errors

Configuration errors can occur when the node setup or inputs are misconfigured and attempts to write to the source cannot succeed. Some examples of misconfiguration include:

• Using an unsupported record type (for example, a record type with a non-database source).
• An error in the related Event History record type or Event Type Lookup record type (for example, a field is deleted or the record type is deleted).
• An error in the expression calling the process model or the a!deleteRecords() function.

Errors with the data source

Appian is unable to change data in the source in some circumstances. These situations include:

• Schema mismatches such as conflicting data types.
• Database connection problems like timeouts or invalid credentials.

If Appian is unable to write to the database, the record data will still remain available even if the smart service fails.

Errors syncing data changes

When Appian attempts to sync changes to the source data, the sync will fail when one of the following occurs:

• The record type's row limit is exceeded.
• A record field contains an invalid value.
• The record type's source filter is invalid (for example, if the source field is no longer available).

If Appian is unable to sync changes from the source, the record data will be unavailable. For more information on the different types of sync errors and steps to resolve these errors, see Troubleshooting Syncs.

Examples

The following examples show the different ways you can use the a!deleteRecords() function to delete your record data.

The following example data is from the Appian Retail application, available for free in Appian Community Edition. To try the example code yourself, sign in to Appian Community to request the latest Appian Community Edition site.

Delete a record using a process model

Imagine you need to remove an Employee from the Appian Retail application. You can let users delete record data using a related action connected to a process model. Set a process variable using the record type as the data type to pass the user's selection to the Delete Records node.

The process node examines the primary key field (in this case, the id field) and deletes that record from the source.

Delete a record using an expression

You can also delete a record using the a!deleteRecords() function. For example, to delete an Address record, use a record type constructor in the records parameter and provide the identifier of the record to be deleted. In the following example, the Address record we want to delete has the addressId value of 322.

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a!deleteRecords(
  records: {
    recordType!Address(
      recordType!Address.fields.addressId: 322
    )
  }
)

The Address record type has other fields (like city and postalCode) which are not included in the expression. Only the primary key is required to identify the record being deleted.

The a!deleteRecords() expression returns data similar to the following:

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countOfRecordsDeleted: 1

Feature compatibility

Versions

A smart service consists of a function and a node. There are some instances when the smart service function is evolved separately from the smart service node. When the function or node is evolved, a new version of the function or node is available.

The following sections detail the different versions of the Delete Records function and Delete Records node.

Node versions

You can identify the version of a smart service node by looking at node type and version.

To review a node's type and version:

1. In the Process Modeler, click Tools > Generate Documentation.
2. In the generated documentation, review the Node Type and Version for the specific node.

If you are using a previous version, be sure to refer to the corresponding documentation from the list below. To use the latest version of the node, replace the old version of the node with a new node.

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