For testing purpose you can set the %ALL role and try test it again 

You can make the call activity to sync by unchecking the Asynchronous check box in the call activity.

Hello @Enrico Parisi 

That's right, However Instead of creating a custom datatype to fix this. create/use the auto generated method for that property "OPDTLogicalToXSD" and implement the code logic.

ClassMethod OPDTLogicalToXSD(%val As %TimeStamp) As %String [ ServerOnly = 1 ]
{
	Set %val=##class(%Library.TimeStamp).LogicalToXSD(%val)
	Quit $translate(%val,"TZ"," ")
}

Hello @Michael Wood

It won't allow to import the array values directly from the response/payload If you're using %JSONImport  in %JSON.Adaptor due to the datatype validation while import. So, You may define the list of properties in separate class definition and use that Property Messages As list of class if the array has object values and It allows to import. Or if it's literal string inside an array then it allows without any issues. 

Sample: Literal string values inside array

Class Samples.NewClass2 Extends (%Persistent, %Populate, %JSON.Adaptor)
{

Property email As list Of %String;

Parameter %JSONIGNOREINVALIDFILED = 1;

Property FirstName As %String;

Property LastName As %String;

ClassMethod test()
{
    set json={"FirstName":"test","LastName":"lastname","email":["test@gmail.com","test2@gmail.com"]}
    set obj= ..%New()
    set st= obj.%JSONImport(json)
    if $$$ISERR(st) write $SYSTEM.OBJ.DisplayError(st)
    write obj.%JSONExport()
}

}

output

LEARNING>d ##Class(Samples.NewClass2).test()
{"email":["test@gmail.com","test2@gmail.com"],"FirstName":"test","LastName":"lastname"}

Hi @Nimisha Joseph 

The query is executed directly when you call. Check this SQL.Statement

set tResult = ##class(%SQL.Statement).%ExecDirect(,"select name,age from Sample.Person")

"And result will be stored in tResult variable. Try executing the below in trace or assign and see 

write tResult.%SQLCODE

write tStatement

Hello @Nimisha Joseph 
As per you're SQL implementation. It's actually straightforward and you took and store "Forename" and "Surname" in to context.  haven't taken any SQL resultset object to loop. You can execute only embedded sql in the <sql> BPL element.

So, If you want to execute the query you can assign the SQL object by using <assign> or you can use code block to write executable codes. I have added some sample code below for reference.

• Assign the SQL result set object to context variable
• while the result set
  • process and result and do your implementation

/// BPL Definition
XData BPL [ XMLNamespace = "http://www.intersystems.com/bpl" ]
{
<process language='objectscript' request='Ens.Request' response='Ens.Response' height='2000' width='2000' >
<context>
<property name='Forename' type='%String' instantiate='0' >
<parameters>
<parameter name='MAXLEN'  value='50' />
</parameters>
</property>
<property name='Surname' type='%String' instantiate='0' >
<parameters>
<parameter name='MAXLEN'  value='50' />
</parameters>
</property>
<property name='ReportDiscipline' type='%String' instantiate='0' >
<parameters>
<parameter name='MAXLEN'  value='50' />
</parameters>
</property>
<property name='tResult' type='%SQL.StatementResult' instantiate='0' />
</context>
<sequence xend='200' yend='950' >
<trace name='TEMP trace element' value='"In business process "_request.StringValue' xpos='200' ypos='250' />
<assign property="context.ReportDiscipline" value="request.StringValue" action="set" xpos='200' ypos='350' />
<trace value='"ReportDiscipline value: "_context.ReportDiscipline' xpos='200' ypos='450' />
<assign property="context.tResult" value="##Class(%SQL.Statement).%ExecDirect(,&quot;select * from table&quot;)" action="set" xpos='200' ypos='550' />
<while condition='context.tResult.%Next()' xpos='200' ypos='650' xend='200' yend='450' >
<assign property="context.surname" value="context.tResult.%Get(&quot;surname&quot;)" action="set" xpos='200' ypos='250' />
</while>
<trace value='"SQLCODE: "_SQLCODE' xpos='200' ypos='750' />
<trace value='"returned value: "_context.Forename' xpos='200' ypos='850' />
</sequence>
</process>
}

HTH.