Question

This is the query I am currently using:

DECLARE @Index AS INT
SET @Index = 1
SELECT
  auditId,
  parameters.value('(params/param[position()=sql:variable("@Index")]/node())[1]', 'nvarchar(256)') AS value,
  parameters.value('(params/param[position()=sql:variable("@Index")]/@entityId)[1]', 'nvarchar(256)') AS entityId,
  parameters.value('(params/param[position()=sql:variable("@Index")]/@entityType)[1]', 'bigint') AS entityType,
  parameters.value('(params/param[position()=sql:variable("@Index")]/@localizable)[1]', 'bit') AS localizable
FROM
  audit

Where my audit table contains a parameters XML node that looks something like this:

UserName
ComputerName

What I am wondering if is there is a way to get rid of the redundant parameters.value('(params/param[position()=sql:variable("@Index")] section and maybe do it as a join?

Answer 1

You can simplify a bit by using cross apply.

SELECT
  auditId,
  T.N.value('.', 'nvarchar(256)') AS value,
  T.N.value('@entityId', 'nvarchar(256)') AS entityId,
  T.N.value('@entityType', 'bigint') AS entityType,
  T.N.value('@localizable', 'bit') AS localizable
FROM audit
  CROSS APPLY parameters.nodes('/params/param[sql:variable("@Index")]') AS T(N)