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Contents
Preface

Virtuoso Functions Guide

Administration
Aggregate Functions
Array Manipulation
BPEL APIs
Backup
Compression
Cursor
Date & Time Manipulation
Debug
Dictionary Manipulation
Encoding & Decoding
File Manipulation
Free Text
Hashing / Cryptographic
LDAP
Locale
Mail
Miscellaneous
Number
RDF data
Remote SQL Data Source
Replication
SOAP
SQL
String
Transaction
Type Mapping
UDDI
User Defined Types & The CLR
Virtuoso Java PL API
Virtuoso Server Extension Interface (VSEI)
Web Server & Internet
XML
XPATH & XQUERY
and
append
assign
avg
boolean
ceiling
concat
contains
count
create-attribute
create-comment
create-element
create-pi
current
distinct
doc
document
document-literal
empty
ends-with
every
except
false
filter
floor
fn:collection
for
format-number
function-available
generate-id
id
if
intersect
is_after()
is_before()
key
lang
last
let
list()
local-name
max
min
name
namespace-uri
normalize-space
not
number
or
position
processxquery
processxslt
processxsql
progn()
replace()
round
serialize
shallow
some
starts-with
string
string-length
substring
substring-after
substring-before
sum
system-property
text_contains()
translate
true
tuple()
union
unordered
unparsed-entity-uri
urlify
xmlview

Functions Index

empty

Returns true if given argument is an empty sequence, false if it is any single value or nonempty sequence.
boolean empty ( seq any);
Description

Returns true if given argument is an empty sequence, false if it is any single value or nonempty sequence.

Parameters
seq – Sequence of values to be checked.
Return Types

Boolean

Errors

This function never returns any errors

Examples
if(empty(//table),'There are no tables in context node','There is at least one table')