Reading xml data in SQL - sql-server

Question

I am reading data from xml in Sql.
Here is my xml :
Declare #MainXml XML =
'<?xml version="1.0" encoding="utf-8"?>
<result>
<details>
<admin>
<code>555</code>
</admin>
<claimhistory>
<claim id="1" number="100">
<account>Closed</account>
</claim>
<claim id="2" number="200">
<account>Closed</account>
</claim>
</claimhistory>
</details>
</result>'
Reading data like this:
select
C.X.value('(admin/code)[1]', 'varchar(max)') as Code,
A.X.value('#id', 'varchar(max)') as Id,
A.X.value('#number', 'varchar(max)') as No,
A.X.value('(account)[1]', 'varchar(max)') as Status
from
#MainXml.nodes('result/details') as C(X)
cross apply
C.X.nodes('claimhistory/claim') as A(X)
This is returning:
Code Id No Status
---------------------
555 1 100 Closed
555 2 200 Closed
Stored procedure contains above code.
Here datatable variable is used as an input for Stored Procedure. It contains id and name.
Declare #dtValue As [dbo].[DataTableDetails]
Insert Into #dtValue(Requested_Id, Name) Values(1, 'Tim');
Insert Into #dtValue(Requested_Id, Name) Values(2, 'Joe');
I want to add these names to select query based on matching Id of an xml to input.
Expected output -
Code Id No Status Name
----------------------------
555 1 100 Closed Tim
555 2 200 Closed Joe
Currently - after inserting the selected records from xml, I am using update query But table contains over a million records so it is effecting performance now.
Please suggest me.
Edited:
Tried with Join - [added below line in select query]
Select
C.X.value('(admin/code)[1]', 'varchar(max)') as Code,
A.X.value('#id', 'varchar(max)') as Id,
A.X.value('#number', 'varchar(max)') as No,
A.X.value('(account)[1]', 'varchar(max)') as Status,
CA.Name
from
#MainXml.nodes('result/details') as C(X)
cross apply
C.X.nodes('claimhistory/claim') as A(X)
join
#dtValue CA on CA.Requested_Id = A.X.value('#id', 'varchar(max)')

Answer 1

I'd recommend refactoring the way you're selecting from the XML like so:
select
C.X.value('(../../admin/code)[1]', 'varchar(max)') as Code,
C.X.value('#id', 'varchar(max)') as Id,
C.X.value('#number', 'varchar(max)') as No,
C.X.value('(account)[1]', 'varchar(max)') as Status,
dt.Name
from
#MainXml.nodes('result/details/claimhistory/claim') as C(X)
INNER JOIN #dtValue dt
ON dt.Requested_Id = C.X.value('(#id)[1]', 'int')
You don't actually want to CROSS APPLY the child nodes, you want them to be the primary part you're selecting from (i.e. one row per claim element) - it's then easy enough to select based on the grandparent node to get the Code value, and then you can properly INNER JOIN your table variable.
Full sample:
Declare #MainXml XML =
'<?xml version="1.0" encoding="utf-8"?>
<result>
<details>
<admin>
<code>555</code>
</admin>
<claimhistory>
<claim id="1" number="100">
<account>Closed</account>
</claim>
<claim id="2" number="200">
<account>Closed</account>
</claim>
</claimhistory>
</details>
</result>'
DECLARE #dtValue TABLE (Requested_Id int, Name varchar(10))
Insert Into #dtValue(Requested_Id, Name) Values(1, 'Tim'), (2, 'Joe');
select
C.X.value('(../../admin/code)[1]', 'varchar(max)') as Code,
C.X.value('#id', 'varchar(max)') as Id,
C.X.value('#number', 'varchar(max)') as No,
C.X.value('(account)[1]', 'varchar(max)') as Status,
dt.Name
from
#MainXml.nodes('result/details/claimhistory/claim') as C(X)
INNER JOIN #dtValue dt
ON dt.Requested_Id = C.X.value('(#id)[1]', 'int')