Question

This site has a technique to pass xml data around in Microsoft SQL Server:

DECLARE @productIds xml
SET @productIds ='<Products><id>3</id><id>6</id><id>15</id></Products>' 

SELECT
ParamValues.ID.value('.','VARCHAR(20)')
FROM @productIds.nodes('/Products/id') as ParamValues(ID) 

But what is the syntax if I add another field?
The following does NOT work:

DECLARE @productIds xml
SET @productIds ='<Products><id>3</id><descr>Three</descr><id>6</id><descr>six</descr><id>15</id><descr>Fifteen</descr></Products>' 

SELECT
ParamValues.ID.value('.','VARCHAR(20)')
,ParamValues.descr.value('.','VARCHAR(20)')
FROM @productIds.nodes('/Products/id') as ParamValues(ID) 

Note: Maybe I’ve constructed my xml wrong.

Answer 1

You need to use something like:

SELECT
    ParamValues.ID.value('(id)[1]','VARCHAR(20)'),
    ParamValues.ID.value('(descr)[1]','VARCHAR(20)')
FROM
    @productIds.nodes('/Products') as ParamValues(ID) 

That FROM statement there defines something like a “virtual table” called ParamValues.ID – you need to select the <Products> node into that virtual table and then access the properties inside it.

Furthermore, your XML structure is very badly chosen:

<Products>
    <id>3</id>
    <descr>Three</descr>
    <id>6</id>
    <descr>six</descr>
    <id>15</id>
    <descr>Fifteen</descr>
</Products>

You won’t be able to select the individual pairs of id/descr – you should use something more like:

<Products>
    <Product>
       <id>3</id>
       <descr>Three</descr>
    </Product>
    <Product>
       <id>6</id>
       <descr>six</descr>
    </Product>
    <Product>
       <id>15</id>
       <descr>Fifteen</descr>
    </Product>
</Products>

Then you could retrieve all items using this SQL XML query:

SELECT
    ParamValues.ID.value('(id)[1]','VARCHAR(20)') AS 'ID',
    ParamValues.ID.value('(descr)[1]','VARCHAR(20)') AS 'Description'
FROM
    @productIds.nodes('/Products/Product') as ParamValues(ID) 

ID    Descrition
 3      Three
 6      six
15      Fifteen