Question

I am working on a migration project and need to convert following Oracle query into it’s SQL Server equivalent.

select SYS_CONNECT_BY_PATH (b.actionnr,'/') as FATHER, SYS_CONNECT_BY_PATH (b.actionnr,'     | ') as REFPATH, LEVEL, 
(select count(p.refactionnr) from zisjob.zj_action p where p.refactionnr=b.actionnr)
Childs, b.* from 
( select NVL(x.ANZFiles,0) ANZFiles, act.actionnr, act.refactionnr, act.lfno, act.jobnr,     act."TYPE", act.actiontype
from zisjob.zj_action act, zisjob.zj_actiontype t, 
( select f.lno, count(f.filenr) as ANZFiles from zisjob.zj_file f where f.lno != f.lfno     Group by f.lno )x
where act.lfno=10 and act.actiontype = t.typeid(+) and act.actionnr = x.lno(+) )
b start with b.actionnr in 
(select b.actionnr from zisjob.zj_action b where b.lfno = 10 and b.refactionnr is    null)
connect by nocycle prior b.actionnr=b.refactionnr order by 1 desc, 2 asc

I am using CTEs to do this. So far, I’ve come up with following :

with h$cte as 
(
   select
      cast (convert(varchar,b.actionnr)+'/' as varchar(max)) as FATHER,
      cast(convert(varchar,b.actionnr)+' | ' as varchar(max)) as REFPATH,
      1 as LEVEL,
      --cast (row_number() over (order by @@spid) as varchar(max)) as LEVEL,
      (select count(p.refactionnr) from zisjob.zj_action p 
       where p.refactionnr = b.actionnr) Childs, 
      b.* 
   from
     (select 
         isnull(x.ANZFiles, 0) ANZFiles, act.actionnr, act.refactionnr, act.lfno,  
         act.jobnr, act."TYPE", act.actiontype
      from zisjob.zj_action act 
      left outer join zisjob.zj_actiontype t on act.actiontype = t.typeid 
      left outer join
          (select f.lno, count(f.filenr) as ANZFiles 
           from zisjob.zj_file f
           where f.lno != f.lfno Group by f.lno ) x on act.actionnr = x.lno
      where act.lfno = 10) b
where 
   b.actionnr in
       (select b.actionnr from zisjob.zj_action b 
        where b.lfno = 10 and b.refactionnr is null)

UNION ALL

select
    CAST(FATHER + '/'+ b.ACTIONNR as varchar(max)) as FATHER,
    CAST(REFPATH + '|'+b.ACTIONNR AS VARCHAR(MAX)) as REFPATH,
    h$cte.LEVEL + 1 as LEVEL,
    (select count(p.refactionnr) from zisjob.zj_action p  
     where p.refactionnr = b.actionnr) Childs, 
    b.*
from
   (select isnull(x.ANZFiles, 0) ANZFiles, act.actionnr, act.refactionnr, 
           act.lfno, act.jobnr, act."TYPE", act.actiontype
    from zisjob.zj_action act 
    left outer join zisjob.zj_actiontype t on act.actiontype = t.typeid 
    left outer join
        (select f.lno, count(f.filenr) as ANZFiles from zisjob.zj_file f
         where f.lno != f.lfno Group by f.lno) x on act.actionnr = x.lno
    where act.lfno = 10) b, 
    h$cte
where 
    b.actionnr in
        (select b.actionnr from zisjob.zj_action b 
         where b.lfno = 10 and b.refactionnr is null)
    and h$cte.ACTIONNR = h$cte.REFACTIONNR
)
select <columns> from h$cte

The translated query giving following errors:

Msg 467, Level 16, State 1, Line 1
GROUP BY, HAVING, or aggregate functions are not allowed in the recursive part of a recursive common table expression ‘h$cte’.

Msg 462, Level 16, State 1, Line 1
Outer join is not allowed in the recursive part of a recursive common table expression ‘h$cte’

How can I work around this? Any help in any form is greatly appreciated. Thanks in advance.

Answer 1

I’ve finally solved this as:

WITH dummy AS(

select isnull(x.ANZFiles,0) ANZFiles, act.actionnr, act.refactionnr, act.lfno, act.jobnr, act."TYPE", act.actiontype

from zisjob.zj_action act left outer join zisjob.zj_actiontype t on act.actiontype = t.typeid left outer join 

( select f.lno, count(f.filenr) as ANZFiles from zisjob.zj_file f 

where f.lno != f.lfno Group by f.lno )x on act.actionnr = x.lno

where act.lfno=10), 

 dummy2 as(

select count(p.refactionnr) as Childs 

from zisjob.zj_action p inner join dummy b on p.refactionnr=b.actionnr

),

h$cte as(

select 

cast ('/'+convert(varchar,b.actionnr) as varchar(max)) as FATHER, 

cast(' | '+convert(varchar,b.actionnr) as varchar(max)) as REFPATH, 

1 as LEVEL,

c.Childs,

--cast (row_number() over (order by @@spid) as varchar(max)) as LEVEL, 

b.* 

from dummy b, dummy2 c

where b.actionnr in 

(select b.actionnr from zisjob.zj_action b where b.lfno = 10 and b.refactionnr is null)

UNION ALL

select

CAST(FATHER + '/'+ b.ACTIONNR as varchar(max)) as FATHER,

CAST(REFPATH + '|'+b.ACTIONNR AS VARCHAR(MAX)) as REFPATH,

h$cte.LEVEL + 1 as LEVEL,c.Childs,

b.*

from dummy b, dummy2 c, h$cte

where b.actionnr in 

(select b.actionnr from zisjob.zj_action b where b.lfno = 10 and b.refactionnr is null)

and h$cte.ACTIONNR = h$cte.REFACTIONNR

)

select * from h$cte

Since I was not allowed to write outer joins and GROUP BY, HAVING, or aggregate functions inside recursive member of CTE, I’ve moved it outside under a new CTE. That worked like a charm.

Cheers !!!