XQuery - Deleting using joins

, ,
1

Hello!

I have problem with a - in my opinion - complex XQuery.

I have three doctypes and want to do a nested delete.

doctype b depends on doctype a
doctype c depends on doctype b

So for example:
If a delete a element in doctype a where aID = 5, i want to delete all doctypes b where aID = bID. So far, seems no problem. But now I also want to delete all doctypes c where $cOtherID = $bOtherID AND the above options matches.

Get all elements with:

for $a in input()/docA
for $b in input()/docB
where $a/ID = $b/ID
and $b/ID = 5
return

{$a/ID}
{$b/otherID}
{for $c in input()/docC
where $c/otherID = $b/otherID
return $c/anotherValue }


It works fine. Gives me a list like that:


5
1
1
3
4


Now, i want to rewrite this query to delete all doctypes a,b and c where the query returns values.

Any ideas? Or should I split this into different queries? One query would be great.

Thanks in advance.

Regards,
Christian

2

Hi,

You can use an FLWU expression to perform the delete operation. The following statement should do the job:

update
for $a in input()/docA
for $b in input()/docB
let $d := for $c in input()/docC
where $c/otherID = $b/otherID
return $c
where $a/ID = $b/ID
and $b/ID = 5
do
(
delete $a
delete $b
delete $d
)

Regards,
Thorsten

3

Hi Thorsten!

Thanks again for your help!

Just one thing missing in your query.
Has to be 

 
do
( 
delete $a/..
delete $b/..
delete $d/..
)



to delete all root element.

Regards,
Christian