Compare two strings.
fn:compare(string $string1, string? $string2) => integer
fn:compare(string $string1, string? $string2, string $collation) => integer
This function compares two strings. If a third parameter is supplied, the strings are compared according to the specified collation. If the third parameter is not supplied, the strings are compared according to the default collation. It returns one of the following integer values:
-1 |
the value of $string1 is
less than that of $string2 |
0 |
the value of $string1 is
equal to that of $string2 |
1 |
the value of $string1 is
greater than that of $string2 |
If no collation is used, Unicode code points are used when comparing.
| $string1 |
string value |
|---|---|
| $string2 |
string value |
| $collation |
string value |
Compare two strings that differ in case:
compare("Tamino", "tamino")
This query returns -1, since the value of
"T" (U+0054) is less than that of
"t" (U+0074).
Perform a case-insensitive comparison:
compare("Tamino", "tamino", "collation?strength=secondary")
This query returns 0, since the values of the strings
"Tamino" and "tamino",
disregarding upper-/lower-case, are equal. The collation strength
"secondary" indicates that primary character
attributes, i.e. the base character itself, and secondary attributes, i.e.
accents, are considered when performing the comparison, but tertiary and
quaternary attributes, which include case information, are ignored. See
tsd:strength for further
information.
Get all patients with the name "Müller":
for $i in input()/patient/name where compare($i/surname, 'Müller', tf:getCollation($i/surname)) = 0 return $i
This query returns the name nodes of all
patients whose surname contains the string value
"Müller" or a string value that is equal to
"Müller" using the collation defined for the element
surname.
The following construct(s) refer to this construct: