SQL select query to get records based on xml node value?

Question

I have a column of ntext data type and NOT XML. It stores all xml data. I need to get records based on xml node value. =>input value is CpsiaId = 456 and should return all records which has this value in the xml

I tried select * from tableName where convert(xml,column_name).value('data((/root/ProductInformation/CPSIA/CpsiaDetails/Item/CpsiaId)[1])','int') = 456

but it didn't work....any ideas or other way of getting the records based xml node value.

Sample Xml:

<root>
  <ProductInformation>
    <Name> Truck with Battery Charger</Name>
    <Description>Fr.</Description>
    <CPSIA>
      <CpsiaDetails>
        <Item>
          <CpsiaId>456</CpsiaId>
          <CpsiaMessage>waring</CpsiaMessage>
        </Item>
        <Item>
          <CpsiaId>236</CpsiaId>
          <CpsiaMessage>to health</CpsiaMessage>
        </Item>
      </CpsiaDetails>
    </CPSIA>
  </ProductInformation>
</root>

Answer 1

convert(xml,column_name).exist('/root/ProductInformation/CPSIA/CpsiaDetails/Item[CpsiaId=456]') = 1

This works, and you can replace the constant (456) with an sql:variable() if you need a dynamic value, like so (assuming a numeric variable @i):

'/root/ProductInformation/CPSIA/CpsiaDetails/Item[CpsiaId=sql:variable("@i")]'

Edit:

Sample code as requested:

DECLARE @t nvarchar(MAX);
SET @t = '<root>
  <ProductInformation>
    <Name> Truck with Battery Charger</Name>
    <Description>Fr.</Description>
    <CPSIA>
      <CpsiaDetails>
        <Item>
          <CpsiaId>456</CpsiaId>
          <CpsiaMessage>waring</CpsiaMessage>
        </Item>
        <Item>
          <CpsiaId>236</CpsiaId>
          <CpsiaMessage>to health</CpsiaMessage>
        </Item>
      </CpsiaDetails>
    </CPSIA>
  </ProductInformation>
</root>'

DECLARE @i int;
SET @i = 456;

SELECT convert(xml,@t).exist('/root/ProductInformation/CPSIA/CpsiaDetails/Item[CpsiaId=sql:variable("@i")]')