How to use openxml within a user defined function in SQL Server - tsql

Question

I have an XML structure that I parse using OPENXML within a stored procedure to retrieve parameters used to perform a query. This procedure was a base procedure that a different stored procedure (procedure 2) is calling. Procedure 2 uses an insert-exec construct to get the data from the base procedure. This works great as long as we only call Procedure 2 or the base procedure.
My first problem is that I have a different procedure (procedure 3) that now needs to get the result from procedure 2 (I need the business rules that this procedure enforces), but cannot due to the message:
An INSERT EXEC statement cannot be nested.
I then tried to take the base procedure and make it a table valued function, but when I execute it, I receive the message:
Only functions and some extended stored procedures can be executed from within a function.
How do I get around one or both of these issues?
EDIT 1
I am including a code snippet to show the base procedure (Procedure 1) and the procedure implementing business requirements on the results of that procedure (Procedure 2). If there is a 3rd procedure that needs the results with the business rules applied, we run into problems.
create procedure dbo.p_Proc
#Xml xml
as
begin
set nocount on;
declare #l_idoc int
, #InfoId int
, #InfoTypeId int
, #Id int
, #Name varchar(50)
, #StatusId int
, #RoleId int
, #XmlBase xml
, #l_path varchar(100);
declare #T_TABLE table(
InfoId int
, InfoTypeId int
);
declare #T_RESULT table
(
Field1 int
, Field2 varchar(50)
, Field3 int
);
EXEC sp_xml_preparedocument #l_idoc OUTPUT, #Xml;
set #l_path = '/xml/Info';
insert into #T_TABLE(InfoId, InfoTypeId)
select InfoId, InfoTypeId
from OPENXML (#l_idoc, #l_path, 1)
with (
InfoId int './#InfoId'
, InfoTypeId int './#InfoTypeId'
);
select #InfoId = InfoId
, #InfoTypeId = InfoTypeId
from #T_TABLE;
-- create the XML to call the base widgets
select #XmlBase =
(
select *
from
(
select t.Id, t.Name, t.StatusId, t.RoleId
from #T_TABLE w
inner join dbo.T_TABLE2 t
on t.InfoId = w.InfoId
and t.InfoTypeId = w.InfoTypeId
) b
for xml raw('Widget'), root('Xml')
);
-- retrieve widgets from base security
insert into #T_RESULT(Field1, Field2, Field3)
exec dbo.p_ProcBase #Xml = #XmlBase;
-- apply business logic here
select w.Field1, w.Field2, w.Field3
from #T_RESULT w;
end;
go
create procedure dbo.p_ProcBase
#Xml xml = null
as
begin
set nocount on;
declare #l_idoc int
, #Id int
, #Name varchar(50)
, #StatusId int
, #RoleId int
, #l_path varchar(100);
declare #T_Table table(
Id int
, Name varchar(50)
, StatusId int
, RoleId int
);
EXEC sp_xml_preparedocument #l_idoc OUTPUT, #Xml;
set #l_path = '/Xml/Widget';
insert into #T_Table(Id, Name, StatusId, RoleId)
select Id, Name, StatusId, RoleId
from OPENXML (#l_idoc, #l_path, 1)
with (
ProjectId int './#Id'
, WidgetTypeName varchar(50) './#Name'
, WorkflowStatusId int './#StatusId'
, UserRoleId bigint './#RoleId'
);
select #Id = w.Id
, #Name = w.Name
, #StatusId = w.StatusId
, #RoleId = w.RoleId
from #T_Table w;
-- retrieve enabled widgets for which the user has a role in the current workflow state
select t.Field1, t.Field2, t.Field3
from dbo.T_TABLE t
where t.StatusId = #StatusId
and t.RoleId = #RoleId;
end;

Answer 1

In order to send a data set (table) between procs, you must use a Table type, store the output of proc2 in a variable of table type and add a readonly only table type parameter to proc3
First you must create a table type to map your output from proc2:
CREATE TYPE T_RESULT AS TABLE
(
Field1 int
, Field2 varchar(50)
, Field3 int
);
In dbo.p_Proc change #T_RESULT to:
declare #T_RESULT T_RESULT
Then create proc3:
CREATE PROCEDURE dbo.proc3
#T_RESULT T_RESULT READONLY
AS
BEGIN
SET NOCOUNT ON
INSERT INTO T3(...)
SELECT ... FROM #T_RESULT
END
Don't forget to add READONLY after a table type parameter in a proc.