How to load entities of which a property of type PersistentList contains one or more values from array parameter? - codefluent

Question

My model contain the following enumeration and entity:
<cf:enumeration name="Language" usePersistenceDefaultValue="false">
<cf:enumerationValue name="EN" value="1" default="true" />
<cf:enumerationValue name="NL" value="2" />
<cf:enumerationValue name="DE" value="3" />
</cf:enumeration>
<cf:entity name="Person" >
<cf:property name="Id" key="true" />
<cf:property name="Languages" typeName="CodeFluent.Runtime.Utilities.PersistentList<Language>">
<cf:message class="_doc">The languages that the person speaks</cf:message>
</cf:property>
<cf:method name="LoadPersonThatSpeaksOneOrMoreLanguages" checkLevel="None" memberAttributes="Public" >
<cf:body language="tsql" text="load(Language[] languages) from Person where Languages in (#languages)" />
</cf:method>
</cf:entity>
The method LoadPersonThatSpeaksOneOrMoreLanguages should return all persons that speak one or more of the provided languages.
The generated stored procedure for this method seems not to be correct:
ALTER PROCEDURE [dbo].[Person_LoadPersonThatSpeaksOneOrMoreLanguages]
(
#languages [dbo].[cf_type_Person_LoadPersonThatSpeaksOneOrMoreLanguages_0] READONLY,
#_orderBy0 [nvarchar] (64) = NULL,
#_orderByDirection0 [bit] = 0
)
AS
SET NOCOUNT ON
DECLARE #_c_languages int; SELECT #_c_languages= COUNT(*) FROM #languages
SELECT DISTINCT [Person].[Person_Id], ...
FROM [Person]
WHERE [Person].[Person_Languages] IN (((SELECT * FROM #languages)))
Question 1:
How can I achieve the desired result?
Should I create a Language entity and specify an 1:n association between Person and Language? I prefer not to have a Language entity.
Or can I specify that the Languages property must be converted to the same type as the table-valued-parameter (cf_type_Person_LoadPersonThatSpeaksOneOrMoreLanguages_0)?
Question 2:
The produced PersonCollection class contains the method LoadPersonThatSpeaksOneOrMoreLanguages. The parameter of this method is of type Language[]. Instead of an array I want an IEnumerable<Language>. How can I specify this in my XML model?

Answer 1

Question 1
The PersistentList is designed to store a collection of simple values (int, string, enum, ...), but not to query them directly in SQL. Indeed the PersistentList is translated to a NVARCHAR column in the database and this column contains values like EN|NL (pipe separated values). The database engine does not know how to extract single values from the string. Maybe you can use the cf_SplitString function to create a table from the column value and do what you want with it, but it does not seem to be the simplest solution...
Depending of your need you can use a multi-valued enumeration:
<cf:enumeration name="Language" flags="true">
<cf:enumerationValue name="Unspecified" /> <!-- value=0 -->
<cf:enumerationValue name="EN" /> <!-- value=1 -->
<cf:enumerationValue name="NL" /> <!-- value=2 -->
<cf:enumerationValue name="FR" /> <!-- value=4 -->
</cf:enumeration>
You can use them with CFQL:
-- Load Persons that speak the specified language
LOAD(Languages) WHERE (Languages & #Languages) = #Languages
-- Load Persons that speak at least one of the specified language
LOAD(Languages) WHERE (Languages & #Languages) <> 0
Of course the latest possibilities is to create a Language entity and use Table Valued Parameters.
http://blog.codefluententities.com/2014/07/16/persistent-list/
http://www.softfluent.com/documentation/Enumerations_Overview.html
Question 2
From the official blog of CodeFluent Entities:

Answer 2

Take what I say with a grain of salt as you are dealing with a topic I have looked into but never implemented. With that said another approach would be to use a multi-valued enumeration (flag)
http://blog.codefluententities.com/2013/05/29/using-flags-enumeration-with-aspnet-mvc-and-codefluent-entities
Using this approach you would create a relationship between the entity and the enumeration instead of making the Languages property a persistent list.
The following mostly works. When using the Modeler to create instances I was not able to select certain combinations of languages. Don't know if this was due to my inexperience in working with and setting up flag enumeration or if there is a flaw in the modeler. But I did manage to create the method and that part appears to be working.
<cf:enumeration name="Language" multivalue="true" usePersistenceDefaultValue="false" namespace="Demo1" categoryPath="/Demo1">
<cf:enumerationValue name="Unspecified" default="true" />
<cf:enumerationValue name="EN" />
<cf:enumerationValue name="NL" />
<cf:enumerationValue name="DE" />
</cf:enumeration>
<cf:entity name="Person" namespace="Demo1">
<cf:property name="Id" key="true" />
<cf:property name="Languages" usePersistenceDefaultValue="false" typeName="{0}.Language" />
<cf:property name="FirstName" />
<cf:property name="LastName" />
<cf:instance>
<cf:instanceValue name="Id">d13447c6-a709-4c87-891d-e83674821915</cf:instanceValue>
<cf:instanceValue name="FirstName">Jon</cf:instanceValue>
<cf:instanceValue name="LastName">Smith</cf:instanceValue>
</cf:instance>
<cf:instance>
<cf:instanceValue name="Id">77e3730c-2cc3-457d-8bc0-d9a5e224b96a</cf:instanceValue>
<cf:instanceValue name="FirstName">Sam</cf:instanceValue>
<cf:instanceValue name="Languages">DE, SP</cf:instanceValue>
<cf:instanceValue name="LastName">Newman</cf:instanceValue>
</cf:instance>
<cf:method name="LoadPersonThatSpeaksOneOrMoreLanguages" body="LOAD() WHERE Languages > 0" />
As I said take what I'm saying with a grain of salt. I ended up using an entity instead of an enumeration but only because that was what I was more familar with and had a deadline.