Query for xml values in sql server

Question

I have xml field in the below table in Data column

ID | website | Data

Following is the xml field

<Product>
 <field name="IsCustomer" type="System.Boolean, mscorlib">
    <boolean>false</boolean>
  </field>
</product>

I need to retrieve all the IsCustomer values in my table.

Following is the code part that I tried so far.

SELECT EMP.ED.value() as EmployeeID
FROM   [dbo].[Products]
CROSS APPLY Data.nodes('/Product/Field[@Name="IsCustomer"]/Boolean') as EMP(ED)

Can anyone please help me?

Answer 1

First of all: XML is strictly case sensitive! Your XML is not even valid... The leading <Product> is another element-name then the closing </product> . As you seem to use lower letters in all places, I changed it this way.

Your own query is close, but wrong with some capital letters and you did not use the .value() -function properly (missing paramters).

Try this:

DECLARE @mockup TABLE(ID INT IDENTITY,Descr VARCHAR(100),Data XML);
INSERT INTO @mockup VALUES
('Your Sample','<product>
 <field name="IsCustomer" type="System.Boolean, mscorlib">
    <boolean>false</boolean>
  </field>
</product>')
,('Your sample plus another field','<product>
 <field name="IsCustomer" type="System.Boolean, mscorlib">
    <boolean>true</boolean>
  </field>
 <field name="SomeOther" type="System.Boolean, mscorlib">
    <boolean>true</boolean>
  </field>
</product>')
,('No "IsCustomer" at all','<product>
 <field name="SomeOther" type="System.Boolean, mscorlib">
    <boolean>true</boolean>
  </field>
</product>')
,('Two of them','<product>
 <field name="IsCustomer" type="System.Boolean, mscorlib">
    <boolean>true</boolean>
  </field>
 <field name="IsCustomer" type="System.Boolean, mscorlib">
    <boolean>false</boolean>
  </field>
</product>');

SELECT * FROM @mockup;

--Your query returning various variants, one of them should be okay for you:

SELECT m.ID
      ,m.Descr
      ,fld.value('(boolean/text())[1]','bit')
FROM @mockup AS m
OUTER APPLY m.Data.nodes('/product/field[@name="IsCustomer"]') AS A(fld);

Answer 2

I already wrote a post about XQuerying which might be helpful to you.

Note: XQuerying is case sensitive and you need to position yourself properly. Take a look at the post i linked, and if it does not help i will update this comment with a solution regarding your query

Update

---

To answer your question

First and foremost you need to have properly formatted XML, which means tags need to match their case sensitivity, and same rule applies when you are referencing a tag in a XQuery.

So one of the solutions would be :

DECLARE @XML as XML
SET @XML = '<Product>
 <field name="IsCustomer" type="System.Boolean, mscorlib">
    <boolean>false</boolean>
  </field>
</Product>'

SELECT EMP.t.value('boolean[1]','varchar(20)') as EmployeeID
FROM   @XML.nodes('/Product/field') as EMP(t)