"If-Then-Else" expressions,
example:
for $x in doc("books.xml")/bookstore/book
return if ($x/@category="CHILDREN")
then <child>{data($x/title)}</child>
else <adult>{data($x/title)}</adult>
Comparisons
In XQuery there are two ways of comparing values.
1. General comparisons: =, !=, <, <=, >, >=
2. Value comparisons: eq, ne, lt, le, gt, ge
The difference between the two comparison methods are shown below.
The following expression returns true if any q attributes have a value greater than 10:
$bookstore//book/@q > 10
The following expression returns true if there is only one q attribute returned by the expression, and its value is greater than 10. If more than one q is returned, an error occurs:
$bookstore//book/@q gt 10
example:
for $x in doc("books.xml")/bookstore/book
return if ($x/@category="CHILDREN")
then <child>{data($x/title)}</child>
else <adult>{data($x/title)}</adult>
Comparisons
In XQuery there are two ways of comparing values.
1. General comparisons: =, !=, <, <=, >, >=
2. Value comparisons: eq, ne, lt, le, gt, ge
The difference between the two comparison methods are shown below.
The following expression returns true if any q attributes have a value greater than 10:
$bookstore//book/@q > 10
The following expression returns true if there is only one q attribute returned by the expression, and its value is greater than 10. If more than one q is returned, an error occurs:
$bookstore//book/@q gt 10
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