How to: Create Delete Actions

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Applies To: Microsoft Dynamics AX 2012 R3, Microsoft Dynamics AX 2012 R2, Microsoft Dynamics AX 2012 Feature Pack, Microsoft Dynamics AX 2012

The DeleteAction element helps maintain database consistency when a record is deleted. Define delete actions to specify what should occur when data being deleted in the current table is related to data in another table.

For example, use a cascading delete action to specify that the system is to delete a customer's address when that customer is deleted from the CustTable table. Another example is to use a restricted delete action to prevent a customer from being deleted from the CustTable if one or more transactions exist for the customer in the CustTrans table.

Use the following best practices.

  • Have a delete action on every relation between two tables.

  • Use table delete actions instead of writing code to specify whether deletes are restricted or cascaded.

    Note

    Delete actions for groups usually don’t exist except when two groups are related. If there are delete actions on a table and DELETE_FROM is in use, performance will be slow.

Add a Delete Action

  1. In the Application Object Tree (AOT), expand the Data Dictionary.

  2. Expand Tables, and then locate the table that you want to add a delete action to.

  3. Click the table, right-click DeleteActions, and then click New DeleteAction.

  4. Right-click the new delete action, and then click Properties.

  5. Select a related table from the Table property list.

  6. Set the DeleteAction property. The following table describes the available values.

Delete Action

Description

Comments

None

Delete action disabled

Cascade

Deletes related records.

Setting the DeleteAction property to Cascade extends the functionality of the table's delete method. As a result, super(), in delete, initiates a cascaded deletion, propagating the delete from table to table.

A cascaded delete is implicitly protected by tts. Database changes aren't committed until the entire transaction is complete.

Example

On the CustTable table, a cascading delete action has been defined for the CustBankAccount table. When a customer is deleted from the CustTable table, the delete method also ensures that the corresponding bank account information is automatically deleted.

Restricted

Restricts deletion in the current table if data is present in related tables.

Setting the DeleteAction property to Restricted extends the functionality of the table's validateDelete method.

As a result, super(), in validateDelete, checks whether records exist on related tables. If records do exist, validateDelete returns false. The forms system ensures that the deletion is not performed. In your own X++ code, check the return value of validateDelete. Don't delete the primary or related records if the method returns false.

Example

On the CustTable table, a restricted delete action has been defined for the CustTrans table. When a customer is deleted in the CustTable table, the validateDelete method ascertains whether transactions exist for the customer in the CustTrans table. If so, validateDelete returns false.

Cascade+Restricted

Cascade the delete, even though records exist on related tables.

Setting the DeleteAction property to Cascade+Restricted extends the functionality of the table's validateDelete and delete methods.

As a result, super(), in validateDelete, ascertains whether records exist on related tables. Whether deleting records from forms or X++, if validateDelete returns false, the primary record isn't deleted and the cascading delete isn't performed. You should first delete the records in the related table before deleting the primary record.

If the primary record is being deleted as part of a cascading delete, the primary record and the records in the related table will be deleted.

Example

The Cascade+Restricted delete action is used in the standard application for LedgerJournalTrans on LedgerJournalTable.

This type of delete action is useful when you prefer a total clean-up—when you delete a customer, you also delete all the transactions associated with that customer.

System tables

Cascading delete also works with Microsoft Dynamics AX system tables. For example, if you delete a user, the system automatically deletes the related information in the UserGroupList table.

See also

Maintaining Data Integrity

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