sqlsql-serverxmlxquery

Getting specific data from XML column


I have the following table in SQL Server 2014:

Table [Product]

Serie,  Int (primary key column)
Name, varchar(100)
LeftMenu, xml

Here is an example of the XML in the LeftMenu column each row could have:

<menu>
<e>
<col>1</col>
<url>
/products/pressure-relief/pressure-relief-valves/general-info
</url>
<IDElement>General-Info
</IDElement>
</e>
<e>
<col>2</col>
<url>
/products/pressure-relief/pressure-relief-valves/parts
</url>
<IDElement>parts
</IDElement>
</e>
</menu>

The expected result is like the following

Serie | col | name
-------------------
1000  |  1  | parts

From a given Serie (the primary key), I want to get the value of the node <col> passing the value of the <IDElement> tag.

It is like searching inside each <IDElement> in the XML and return the value of the <col> tag that matches that group of elements.

I am trying the following but somehow it is not working:

select p.serie, p.name,
pref.value('(col())[1]', 'varchar(max)') as MenuName,
from prodInfo p 
p.[left-menu].nodes('menu/e') as names  (pref)
WHERE  
pre.value('(IDElement())[1]', 'varchar(max)') == @IDElement
AND p.serie =@serie

Could you please tell me what is wrong?

Other option my partner suggested is to do it as in old times and create a new table instead of using XML, any suggestions?

Thank you!


Solution

  • I commented the WHERE to illustrate PARTS is Col 2, OR I completely misunderstood your requirements

    Declare @YourTable table (Series int,Name varchar(100),LeftMenu xml)
    Insert Into @YourTable values
    (1000,'Some Series Name','<menu><e><col>1</col><url>/products/pressure-relief/pressure-relief-valves/general-info</url><IDElement>General-Info</IDElement></e><e><col>2</col><url>/products/pressure-relief/pressure-relief-valves/parts</url><IDElement>parts</IDElement></e></menu>')
    
    Declare @Fetch varchar(100) = 'Parts'
    
    Select A.Series
          ,B.*
     From  @YourTable A
     Cross Apply (
                    Select  Col  = B.value('col[1]','int') 
                           ,Name = B.value('IDElement[1]','varchar(100)') 
                           ,URL  = B.value('url[1]','varchar(100)') 
                    From LeftMenu.nodes('/menu') AS A(Grp)
                    Cross Apply A.Grp.nodes('e') AS B(B)
                    --Where  B.value('IDElement[1]','varchar(100)') = @Fetch
                 ) B
    

    Returns

    Series  Col Name            URL
    1000    1   General-Info    /products/pressure-relief/pressure-relief-valves/general-info
    1000    2   parts           /products/pressure-relief/pressure-relief-valves/parts