XQuery TutorialLesson 68Free preview

XQuery FLWOR

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Summary

FLWOR stands for For, Where, Order by, and P0 which is the most powerful query form in XQuery. This pattern allows iteration, variable shelter, filtering, sequencing, and the formation of results in one expression. FLWOR is a practical matching of SQL SELECT familiar to programmers.

Key points

For: repeat each item sequence into a variable, for example for $x in...
Let: attaching value to a variable without iteration
Where: filter items based on boolean conditions
Order by: sort the results (order by $x/title ascending)
Return: compulsory, determining the output form of each iteration

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