Question

I need to pull a different <node> for each row in the table, the position of the node is stored in SpecificNode

DECLARE @table TABLE
    (
        XmlValue XML,
        SpecificNode INT
    )

INSERT INTO @table SELECT   '<root><node>Y</node><node>Y</node><node>10</node><node>YARD</node></root>', 3
INSERT INTO @table SELECT   '<root><node>N</node><node>20</node><node>PART</node><node></node><node>PASS</node></root>', 2
INSERT INTO @table SELECT   '<root><node>Y</node><node>30</node><node>FORK</node></root>', 2

I can pull a specified node, but when I try to make it dynamic it give me the error “The argument 1 of the xml data type method “value” must be a string literal.”

SELECT  
    XmlValue.value('(/root/node)['+SpecificNode+']', 'VARCHAR(100)')
FROM @table AS tbl

Same error with this

SELECT
    x.value,
    XmlValue.value(x.value, 'VARCHAR(100)')
FROM @table AS tbl
CROSS APPLY (SELECT '(/root/node)['+CONVERT(VARCHAR, SpecificNode)+']' as value) X

My expected output would be

10
20
30

Answer 1

You can use sql:column

SELECT
  XmlValue.value('(/root/node[sql:column("SpecificNode")])[1]', 'VARCHAR(100)')
FROM @table AS tbl