SQL-007: Check preference existence

This scalar Count(*) check determines whether a matching USER_PREFERENCE row already exists for the given application/user (and optional page name). It backs PreferenceData.DoesPrefExist, called from SavePreferences to decide whether to dispatch to UpdatePref or InsertPref.

Classification

Field	Value
SQL ID	SQL-007
Operation type	Read
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	DoesPrefExist

Parameters

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

Tables

Table	Access	Columns used
USER_PREFERENCE	SELECT	USER_ID, APP_NAME, PAGE_NAME

Sample SQL

-- Default form (no page name supplied)
select Count(*)
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:
select Count(*)
from USER_PREFERENCE
where USER_ID = :userid
  and APP_NAME = :appname
  and PAGE_NAME = :pagename

Operations and processes

• Check preference existence
• Save (upsert/delete) preference

Business rules

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

Sources

• SAIF.Framework.Preferences\PreferenceData.cs