Select nodes based on a value range.
You can select nodes based on a value range, with the limiting values
separated by a comma. The range is inclusive of the limiting values. If the
first value is larger than the second, the values are implicitly exchanged. The
comparison depends on the datatype of the node. If you compare a string value
(Literal) with a string range, then a lexical comparison is
performed using the lexicographical order. If you compare a string value with a
numeric range or a numeric value with a string range, then any string values
are implicitly converted to numbers and a numeric comparison takes place. If
the string cannot be converted to a numeric value, then the conversion yields
the special value "NaN" and the comparison
fails.
You can think of BetweenExpr as a convenient abbreviation
for logical conjunctions of RelationalExpr, see the compatibility
note for an example.
You can use betw as a shorthand for between.
However, both variants must be input in lower case.
There is no BetweenExpr defined in XPath. For numeric
values, you can simulate this by using relational expressions. The second
example below could be rewritten as:
//doctor[@pager >= 2 and @pager <= 5]
As RelationalExpr restricts comparison to numeric values,
you cannot in general formulate an equivalent XPath expression for the first
example.
Number and Literal correspond to the
respective XPath expressions, as defined in the
Section 3.7,
Rules 30 and 29.
Select all doctors whose pager numbers start with
"2", "3",
"4" (starting from the root node select all
descendant doctor nodes that satisfy the following predicate
expression: the string value of the pager attribute is
lexicographically ordered between "2" and
"5"):
//doctor[@pager between '2','5']
Select all doctors whose pager numbers are between 2 and 5 (all
doctor nodes that satisfy the following predicate expression: the
string value of the pager attribute implicitly converted to a
number falls into the interval [2,5]). With our example data, this yields an
empty node-set.
//doctor[@pager between 2,5]
Select all doctors whose pager numbers are between 2 and 5 (all
doctor nodes that satisfy the following predicate expression: the
string value of the pager attribute explicitly converted to a
number falls into the interval [2,5]). As before, this yields an empty
node-set.
//doctor[number(@pager) between 2,5]
Select all patients born in the 1950's (all patient nodes
that satisfy the following predicate expression: there is an immediate child
element born whose numeric value is between 1950 and 1959):
/patient[born between 1959,1950]
Tip:
Use BetweenExpr instead of AndExpr where
possible. Usually a query such as //patient[born between 1950,
1953] is much more efficient than the equivalent query expression
//patient[born > 1949 and born < 1954].
SequenceExpr |
