updating inside map:for-each

How can database updating be done inside map:for-each ?

The higher-order functions of the XQuery spec are currently restricted to non-updating functions. You can circumvent this restriction by enabling the MIXUPDATES option, or using traditional iterations (which are, at least, not much slower than map:for-each):

  for $key in map:keys($map)
  let $val := $map($key)
  return (...)

The higher-order functions of the XQuery spec are currently restricted to non-updating functions. You can circumvent this restriction by enabling the MIXUPDATES option, or using traditional iterations (which are, at least, not much slower than map:for-each):

      for $key in map:keys($map)
      let $val := $map($key)
      return (...)

I will offer that if the question is being asked because it matches what would be done in other languages, it’s probably a good idea to read about functional programming, which XQuery is associated with. A purely functional program would not directly cause side-effects within a function. At least, some familiarity with functional programming is fundamentally important in learning about XQuery. Kendall