Creating a view based on XMLType col

Question

I have a table with one column EMPDATA of type XMLTYPE. I have one record in the table with the following xml data:
<Employee xmlns="http://www.oracle.com/empl2.xsd" xmlns:xdb="http://xmlns.oracle.com/xdb" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
     <EmployeeId>2</EmployeeId>
     <Name>String</Name>
     <Job>String</Job>
     <Manager>2</Manager>
     <HireDate>1967-08-13</HireDate>
     <Salary>2</Salary>
     <Commission>2</Commission>
     <Dept>
          <DeptNo>2</DeptNo>
          <DeptName>Dept Name 1</DeptName>
          <Location>Location 1</Location>
     </Dept>
     <Dept>
          <DeptNo>2</DeptNo>
          <DeptName>Dept Name 2</DeptName>
          <Location>Location 2</Location>
     </Dept>
</Employee>
I want to create a view of DeptNo nodes such that I can use standard SQL to query. Since it's possible to have multiple of such nodes, per oracle tutorial a function needs to be created that will return a TableType (I created a tabletype that contains rows of Dept2_Type object types) and I use this function when creating the DeptView:
here is the function:
(deptData in sys.XMLTYPE)
return EMP2_DEPT_TABLE
pipelined is
DEPTS sys.XMLTYPE;
DEPT sys.XMLTYPE;
DeptNo number;
I binary_integer := 1;
DeptName varchar2(40);
Location varchar2(40);
begin
DEPTS := deptData.extract('//Dept');
loop
DEPT:=DEPTS.extract('/Dept['||I||']');
exit when DEPT is null;
DeptName := DEPT.extract('/Dept/DeptName/text()').getStringVal;
DeptNo := DEPT.extract('/Dept/DeptNo/text()').getNumberVal;
Location := DEPT.extract('/Dept/Location/text()').getStringVal;
pipe row (DEPT2_T(null,DeptNo,DeptName,Location));
I := I + 1;
end loop;
return;
end;
here is the code for the view:
select
sys.xmlType.getNumberVal(sys.xmlType.extract(E.EMPDATA,'/Employee/EmployeeId/text()'))
"EId",
D.DeptNo,D.DName,D.Loc
from EMP2 E, table(GET_EMP2_DEPTS(E.EMPDATA)) D
when I query the DeptView I get no records back eventhough there is a record.
Also if I create a slightly different view of dept:
select
sys.xmlType.getNumberVal(sys.xmlType.extract(E.EMPDATA,'/Employee/Dept/DeptNo/text()'))
"DeptNo",
sys.xmlType.getStringVal(sys.xmlType.extract(E.EMPDATA,'/Employee/Dept/DeptName/text()'))
"DeptName",
sys.xmlType.getStringVal(sys.xmlType.extract(E.EMPDATA,'/Employee/Dept/Location/text()'))
"Location",
sys.xmlType.getNumberVal(sys.xmlType.extract(E.EMPDATA,'/Employee/EmployeeId/text()'))
"EmployeeID"
from EMP2 E
and query thais view I get back one record where DeptName and Location columns have the 2 values in one tuple:
'Dept Name 1 Dept Name 2' 'Location 1Location 2'
what I want to see is 2 records returned:
Dept Name 1 Location 1
Dept Name 2 Location 2
has anyone tried this before?
thanks in advance

Answer 1

Hi Joe,
I had a quick look into the files you send me.
The problem is caused by the definition of the return value for the function.
You used:
CREATE Function Batch_Tanks_List (ID INTEGER)
    RETURNS VARCHAR AS
VAR
    Tanks    Varchar (100) ;
    BatchTank Varchar (100) ;
TRY
RETURN ltrim (Tanks, ', ') ;
create or replace view test as select batch_tanks_list (id) namel from batches
Because of the unknown size of the return value the view cannot be created.
If you use CHAR(100) as return value it should work w/o problems:
CREATE Function Batch_Tanks_List (ID INTEGER)
    RETURNS CHAR(100) AS
VAR
    Tanks    Varchar (100) ;
    BatchTank Varchar (100) ;
TRY
RETURN ltrim (Tanks, ', ') ;
create or replace view test as select batch_tanks_list (id) namel from batches
I believe that currently the feature of variable length return values to be used in views is not yet supported, but I would need to check this further.
KR Lars