SQL-006: Delete preference row

This DELETE removes a preference row for a given application/user combination, optionally scoped to a specific page name. It backs PreferenceData.DeletePref, invoked from SavePreferences when the supplied preference text is empty or whitespace-only.

Classification

Field	Value
SQL ID	SQL-006
Operation type	Delete
Execution method	Inline SQL (SqlHelper.ScalarQuery<int>.Execute)
Database	Oracle
Schema	[unqualified]**
Command type	Text
Business object	PreferenceData
Criteria property	n/a (no IBusinessCriteria)
Lifecycle method	DeletePref

Parameters

Parameter	Direction	Type	Max length	Description
:userid	Input	string (SqlHelper.NewParm)	40	Lower-cased user ID; row-selection predicate for delete.
:appname	Input	string (SqlHelper.NewParm)	40	Application name; row-selection predicate for delete.
:pagename	Input	string (SqlHelper.NewParm)	40	Optional page name; only bound when pageName is non-empty.

Tables

Table	Access	Columns used
USER_PREFERENCE	DELETE	USER_ID, APP_NAME, PAGE_NAME

Sample SQL

-- Default form (no page name supplied)
Delete from USER_PREFERENCE
where USER_ID = :userid
  and APP_NAME = :appname
  and PAGE_NAME is NULL

-- When pageName is supplied, the final predicate is replaced with:
Delete from USER_PREFERENCE
where USER_ID = :userid
  and APP_NAME = :appname
  and PAGE_NAME = :pagename

Operations and processes

• Delete preference row
• Save (upsert/delete) preference

Business rules

• BR-001: User IDs are normalized to lower case
• BR-002: Empty preference text triggers deletion
• BR-003: Preference identity is scoped by app, user, and optional page

Sources

• SAIF.Framework.Preferences\PreferenceData.cs