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<h2 class="title">
<a name="builtinfunctions-chapt"></a>Chapter&nbsp;10.&nbsp;Built In Functions</h2>
</div>
<div>
<div class="authorgroup">
<div class="author">
<h3 class="author">
<span class="firstname">Fred</span> <span class="surname">Toussi</span>
</h3>
<div class="affiliation">
<span class="orgname">The HSQL Development Group<br>
</span>
</div>
</div>
</div>
</div>
<div>
<p class="releaseinfo">$Revision: 3601 $</p>
</div>
<div>
<div class="legalnotice">
<a name="N12B56"></a>
<p>Copyright 2010 Fred Toussi. Permission is granted to distribute
this document without any alteration under the terms of the HSQLDB
license. Additional permission is granted to the HSQL Development Group
to distribute this document with or without alterations under the terms
of the HSQLDB license.</p>
</div>
</div>
<div>
<p class="pubdate">$Date: 2010-05-31 20:17:47 -0400 (Mon, 31 May 2010) $</p>
</div>
</div>
</div>
<div class="toc">
<p>
<b>Table of Contents</b>
</p>
<dl>
<dt>
<span class="section"><a href="builtinfunctions-chapt.html#builtin_functions_intro-sect">Overview</a></span>
</dt>
<dt>
<span class="section"><a href="builtinfunctions-chapt.html#builtin_functions_string-sect">String and Binary String Functions</a></span>
</dt>
<dt>
<span class="section"><a href="builtinfunctions-chapt.html#builtin_functions_numeric-sect">Numeric Functions</a></span>
</dt>
<dt>
<span class="section"><a href="builtinfunctions-chapt.html#builtin_functions_datetime-sect">Date Time and Interval Functions</a></span>
</dt>
<dt>
<span class="section"><a href="builtinfunctions-chapt.html#N132C8">Array Functions</a></span>
</dt>
<dt>
<span class="section"><a href="builtinfunctions-chapt.html#N132FD">General Functions</a></span>
</dt>
<dt>
<span class="section"><a href="builtinfunctions-chapt.html#builtin_functions_sysfunc-sect">System Functions</a></span>
</dt>
</dl>
</div>
<div class="section" lang="en">
<div class="titlepage">
<div>
<div>
<h2 class="title" style="clear: both">
<a name="builtin_functions_intro-sect"></a>Overview</h2>
</div>
</div>
</div>
<p>HyperSQL supports a wide range of built-in functions and allows
user-defined functions written in SQL and Java languages. User defined
functions are covered in a separate chapter. If a built-in function is not
available, you can write your own using SQL. Aggregate functions are
discussed in chapters that cover SQL in general.</p>
<p>The built-in functions fall into three groups:</p>
<p>
<div class="itemizedlist">
<ul type="disc">
<li>
<p>SQL Standard Functions</p>
<p>A wide rang of functions defined by SQL/Foundation are
supported. SQL/Foundation functions that have no parameter are
called without empty parentheses. Functions with multiple parameters
often use keywords instead of commas to separate the parameters.
Many functions are overloaded. Among these, some have one or more
optional parameters that can be omitted, while the return type of
some functions is dependent upon the type of one of the parameters.
The usage of SQL Standard Functions (where they can be used) is
covered more extensively in the <a class="link" href="dataaccess-chapt.html" title="Chapter&nbsp;7.&nbsp;Data Access and Change">Data Access and Change</a> chapter</p>
</li>
<li>
<p>JDBC Open Group CLI Functions</p>
<p>These functions were defined as an extension to the CLI
standard, which is the basis for ODBC and JDBC and supported by many
database products. JDBC supports an escape mechanism to specify
function calls in SQL statements in a manner that is independent of
the function names supported by the target database engine. For
example <code class="literal">SELECT {fn DAYOFMONTH (dateColumn)} FROM
myTable</code> can be used in JDBC and is translated to Standard
SQL as <code class="literal">SELECT EXTRACT (DAY_OF_MONTH FROM dateColumn) FROM
myTable</code> if a database engine supports the Standard syntax.
If a database engine does not support Standard SQL, then the
translation will be different. HyperSQL supports all the function
names specified in the JDBC specifications as native functions.
Therefore, there is no need to use the <code class="literal">{fn FUNC_NAME ( ...
) }</code> escape with HyperSQL. If a JDBC function is supported
by the SQL Standard in a different form, the SQL Standard form is
the preferred form to use.</p>
</li>
<li>
<p>HyperSQL Built-In Functions</p>
<p>Several additional built-in functions are available for some
useful operations. Some of these functions return the current
setting for the session and the database. The General Functions
accept arguments of different types and return values based on
comparison between the arguments.</p>
</li>
</ul>
</div>
</p>
<p>In the BNF specification used here, words in capital letters are
actual tokens. Syntactic elements such as expressions are enclosed in
angle brackets. The <code class="literal">&lt;left paren&gt;</code> and
<code class="literal">&lt;right paren&gt;</code> tokens are represented with the
actual symbol. Optional elements are enclosed with square brackets (
<code class="literal">&lt;left bracket&gt;</code> and <code class="literal">&lt;right
bracket&gt;</code> ). Multiple options for a required element are
enclosed with braces (<code class="literal"> &lt;left brace&gt;</code> and
<code class="literal">&lt;right brace&gt;</code> )<code class="literal">.</code> Alternative
tokens are separated with the vertical bar ( <code class="literal">&lt;vertical
bar&gt;</code> ). At the end of each function definition, the standard
which specifies the function is noted in parentheses as JDBC or HyperSQL,
unless the function is in the SQL/Foundation part of the SQL
Standard.</p>
</div>
<div class="section" lang="en">
<div class="titlepage">
<div>
<div>
<h2 class="title" style="clear: both">
<a name="builtin_functions_string-sect"></a>String and Binary String Functions</h2>
</div>
</div>
</div>
<p>In SQL, there are three kinds of string: character, binary and bit.
The units are respectively characters, octets, and bits. Each kind of
string can be in different data types. CHAR, VARCHAR and CLOB are the
character data types. BINARY, VARBINARY and BLOB are the binary data
types. BIT and BIT VARYING are the bit string types. In all string
functions, the position of a unit of the string within the whole string is
specified from 1 to the length of the whole string. In the BNF,
<code class="literal">&lt;char value expr&gt; </code>indicates any valid SQL
expression that evaluates to a character type. Likewise,
<code class="literal">&lt;binary value expr&gt; </code>indicates a binary type
and<code class="literal"> &lt;num value expr&gt; </code>indicates a numeric
type.</p>
<a name="N12BA8" class="indexterm"></a>
<p>
<span class="bold"><strong>ASCII</strong></span>
</p>
<p>
<code class="literal">ASCII ( &lt;char value expr&gt; )</code>
</p>
<p>Returns an INTEGER equal to the ASCII code value of the first
character of <code class="literal">&lt;char value expr&gt;</code>. (JDBC)</p>
<p>
<code class="literal">CHAR ( &lt;UNICODE code&gt; ) </code>
</p>
<p>The argument is an INTEGER. Returns a character string containing a
single character that has the specified<code class="literal"> &lt;UNICODE
code&gt;</code>, which is an integer. ASCII codes are a subset of the
allowed values for <code class="literal">&lt;UNICODE code&gt;</code>. (JDBC)</p>
<a name="N12BC4" class="indexterm"></a>
<p>
<span class="bold"><strong>CONCAT</strong></span>
</p>
<p>
<code class="literal">CONCAT ( &lt;char value expr 1&gt;, &lt;char value expr
2&gt; )</code>
</p>
<p>
<code class="literal">CONCAT ( &lt;binary value expr 1&gt;, &lt;binary value expr
2&gt; )</code>
</p>
<p>The arguments are character strings or binary strings. Returns a
string formed by concatenation of the arguments. Equivalent to the SQL
concatenation expression <code class="literal">&lt;value expr 1&gt; || &lt;value expr
2&gt;</code>. (JDBC)</p>
<a name="N12BD8" class="indexterm"></a>
<p>
<span class="bold"><strong>DIFFERENCE</strong></span>
</p>
<p>
<code class="literal">DIFFERENCE ( &lt;char value expr 1&gt;, &lt;char value expr
2&gt; )</code>
</p>
<p>The arguments are character strings. Converts the arguments into
SOUNDEX codes, and returns an INTEGER between 0-4 which indicates how
similar the two SOUNDEX value are. If the values are the same, it returns
4, if the values have no similarity, it returns 0. In-between values are
returned for partial similarity. (JDBC)</p>
<a name="N12BE6" class="indexterm"></a>
<p>
<span class="bold"><strong>INSERT</strong></span>
</p>
<p>
<code class="literal">INSERT ( &lt;char value expr 1&gt;, &lt;offset&gt;,
&lt;length&gt;, &lt;char value expr 2&gt; )</code>
</p>
<p>Returns a character string based on <code class="literal">&lt;char value expr
1&gt;</code> in which <code class="literal">&lt;length&gt;</code> characters have
been removed from the <code class="literal">&lt;offset&gt;</code> position and in
their place, the whole <code class="literal">&lt;char value expr 2&gt;</code> is
copied. Equivalent to SQL/Foundation <code class="literal">OVERLAY( &lt;char value
expr1&gt; PLACING &lt; char value expr2&gt; FROM &lt;offset&gt; FOR
&lt;length&gt; )</code> . (JDBC)</p>
<a name="N12C03" class="indexterm"></a>
<p>
<span class="bold"><strong>HEXTORAW</strong></span>
</p>
<p>
<code class="literal">HEXTORAW( &lt;char value expr&gt; )</code>
</p>
<p>Returns a BINARY string formed by translation of hexadecimal digits
and letters in the &lt;<code class="literal">char value expr&gt;</code>. Each
character of the <code class="literal">&lt;char value expr&gt;</code> must be a
digit or a letter in the A | B | C | D | E | F set. Each byte of the
retired binary string is formed by translating two hex digits into one
byte. (HyperSQL)</p>
<a name="N12C17" class="indexterm"></a>
<p>
<span class="bold"><strong>LCASE</strong></span>
</p>
<p>
<code class="literal">LCASE ( &lt;char value expr&gt; ) </code>
</p>
<p>Returns a character string that is the lower case version of the
<code class="literal">&lt;char value expr&gt;</code>. Equivalent to SQL/Foundation
<code class="literal">LOWER (&lt;char value expr&gt;)</code>. (JDBC)</p>
<a name="N12C2B" class="indexterm"></a>
<p>
<span class="bold"><strong>LEFT</strong></span>
</p>
<p>
<code class="literal">LEFT ( &lt;char value expr&gt;, &lt;length&gt; )
</code>
</p>
<p>Returns a character string consisting of the first
<code class="literal">&lt;length&gt;</code> characters of <code class="literal">&lt;char value
expr&gt;</code>. Equivalent to SQL/Foundation<code class="literal">
SUBSTRING(&lt;char value expr&gt; FROM 0 FOR &lt;length&gt;)</code>.
(JDBC)</p>
<a name="N12C42" class="indexterm"></a>
<p>
<span class="bold"><strong>LENGTH</strong></span>
</p>
<p>
<code class="literal">LENGTH ( &lt;char value expr&gt; ) </code>
</p>
<p>Returns as a BIGINT value the number of characters in
<code class="literal">&lt;char value expr&gt;</code>. Equivalent to SQL/Foundation
<code class="literal">CHAR_LENGTH(&lt;char value expr&gt;)</code>. (JDBC)</p>
<a name="N12C56" class="indexterm"></a>
<p>
<span class="bold"><strong>LOCATE</strong></span>
</p>
<p>
<code class="literal">LOCATE ( &lt;char value expr 1&gt;, &lt;char value expr
2&gt; [ , &lt;offset&gt; ] ) </code>
</p>
<p>Returns as a BIGINT value the starting position of the first
occurrence of <code class="literal">&lt;char value expr 1&gt;</code> within
<code class="literal">&lt;char value expr 2&gt;</code>. If
<code class="literal">&lt;offset</code>&gt; is specified, the search begins with the
position indicated by <code class="literal">&lt;offset&gt;</code>. If the search is
not successful, 0 is returned. Equivalent to SQL/Foundation
<code class="literal">POSITION(&lt;char value expr 1&gt; IN &lt;char value expr
2&gt;)</code>. (JDBC)</p>
<a name="N12C73" class="indexterm"></a>
<p>
<span class="bold"><strong>LTRIM</strong></span>
</p>
<p>
<code class="literal">LTRIM ( &lt;char value expr&gt; ) </code>
</p>
<p>Returns a character string based on <code class="literal">&lt;char value
expr&gt;</code> with the leading space characters removed. Equivalent
to SQL/Foundation <code class="literal">TRIM( LEADING ' ' FROM &lt;char value expr&gt;
)</code>. (JDBC)</p>
<a name="N12C87" class="indexterm"></a>
<p>
<span class="bold"><strong>RAWTOHEX</strong></span>
</p>
<p>
<code class="literal">RAWTOHEX( &lt;binary value expr&gt; )</code>
</p>
<p>Returns a character string composed of hexadecimal digits
representing the bytes in the <code class="literal">&lt;binary value
expr&gt;</code>. Each byte of the <code class="literal">&lt;binary value
expr&gt;</code> is translated into two hex digits. (HyperSQL)</p>
<a name="N12C9B" class="indexterm"></a>
<p>
<span class="bold"><strong>REGEXP_MATCHES</strong></span>
</p>
<p>
<code class="literal">REGEXP_MATCHES ( &lt;char value expr&gt;, &lt;regular
expression&gt; ) </code>
</p>
<p>Returns true if the &lt;char value expr&gt; matches the &lt;regular
expression&gt;. The &lt;regular expression&gt; is defined according to
Java language rules. (HyperSQL)</p>
<a name="N12CA9" class="indexterm"></a>
<p>
<span class="bold"><strong>REPEAT</strong></span>
</p>
<p>
<code class="literal">REPEAT ( &lt;char value expr&gt;, &lt;count&gt; )
</code>
</p>
<p>Returns a character string based on<code class="literal"> &lt;char value
expr&gt;</code>, repeated <code class="literal">&lt;count&gt;</code> times.
(JDBC)</p>
<a name="N12CBD" class="indexterm"></a>
<p>
<span class="bold"><strong>REPLACE</strong></span>
</p>
<p>
<code class="literal">REPLACE ( &lt;char value expr 1&gt;, &lt;char value expr
2&gt;, &lt;char value expr 3&gt; )</code>
</p>
<p>Returns a character string based on <code class="literal">&lt;char value expr
1&gt;</code> where each occurrence of <code class="literal">&lt;char value expr
2&gt;</code> has been replaced with a copy of <code class="literal">&lt;char value
expr 3&gt;</code>. (JDBC)</p>
<a name="N12CD4" class="indexterm"></a>
<p>
<span class="bold"><strong>REVERSE</strong></span>
</p>
<p>
<code class="literal">REVERSE ( &lt;char value expr&gt; )</code>
</p>
<p>Returns a character string based on <code class="literal">&lt;char value
expr&gt;</code> with characters in the reverse order. (HyperSQL)</p>
<a name="N12CE5" class="indexterm"></a>
<p>
<span class="bold"><strong>RIGHT</strong></span>
</p>
<p>
<code class="literal">RIGHT ( &lt;char value expr&gt;, &lt;count&gt; )
</code>
</p>
<p>Returns a character string consisting of the last
<code class="literal">&lt;count&gt;</code> characters of <code class="literal">&lt;char value
expr&gt;</code>. (JDBC)</p>
<a name="N12CF9" class="indexterm"></a>
<p>
<span class="bold"><strong>RTRIM</strong></span>
</p>
<p>
<code class="literal">RTRIM ( &lt;char value expr&gt; ) </code>
</p>
<p>Returns a character string based on <code class="literal">&lt;char value
expr&gt;</code> with the trailing space characters removed. Equivalent
to SQL/Foundation <code class="literal">TRIM(TRAILING ' ' FROM &lt;character
string&gt;)</code>. (JDBC)</p>
<a name="N12D0D" class="indexterm"></a>
<p>
<span class="bold"><strong>SOUNDEX</strong></span>
</p>
<p>
<code class="literal">SOUNDEX ( &lt;char value expr&gt; ) </code>
</p>
<p>Returns a four character code representing the sound of
<code class="literal">&lt;char value expr&gt;</code>. The US census algorithm is
used. For example the soundex value for Washington is W252. (JDBC)</p>
<a name="N12D1E" class="indexterm"></a>
<p>
<span class="bold"><strong>SPACE</strong></span>
</p>
<p>
<code class="literal">SPACE ( &lt;count&gt; ) </code>
</p>
<p>Returns a character string consisting of <code class="literal">&lt;count&gt;
</code>spaces. (JDBC)</p>
<a name="N12D2F" class="indexterm"></a>
<p>
<span class="bold"><strong>SUBSTR</strong></span>
</p>
<p>
<code class="literal">{ SUBSTR | SUBSTRING } ( &lt;char value expr&gt;,
&lt;offset&gt;, &lt;length&gt; )</code>
</p>
<p>The JDBC version of SQL/Foundation <code class="literal">SUBSTRING</code>
returns a character string that consists of
<code class="literal">&lt;length&gt;</code> characters from <code class="literal">&lt;char value
expr&gt; </code>starting at the <code class="literal">&lt;offset&gt;</code>
position. (JDBC)</p>
<a name="N12D49" class="indexterm"></a>
<p>
<span class="bold"><strong>UCASE</strong></span>
</p>
<p>
<code class="literal">UCASE ( &lt;char value expr&gt; ) </code>
</p>
<p>Returns a character string that is the lower case version of the
<code class="literal">&lt;char value expr&gt;</code>. Equivalent to SQL/Foundation
<code class="literal">UPPER( &lt;char value expr&gt; )</code> . (JDBC)</p>
<a name="N12D5D" class="indexterm"></a>
<p>
<span class="bold"><strong>CHARACTER_LENGTH</strong></span>
</p>
<p>
<code class="literal">{ CHAR_LENGTH | CHARACTER_LENGTH } ( &lt;char value
expression&gt; [ USING { CHARACTERS | OCTETS } ] )</code>
</p>
<a name="N12D69" class="indexterm"></a>
<p>
<span class="bold"><strong>OCTET_LENGTH</strong></span>
</p>
<p>
<code class="literal">OCTET_LENGTH ( &lt;string value expression&gt;
)</code>
</p>
<a name="N12D75" class="indexterm"></a>
<p>
<span class="bold"><strong>BIT_LENGTH</strong></span>
</p>
<p>
<code class="literal">BIT_LENGTH ( &lt;string value expression&gt;
)</code>
</p>
<p>The CHAR_LENGTH or CHARACTER_LENGTH function can be used with
character strings, while OCTET_LENGTH can be used with character or binary
strings and BIT_LENGTH can be used with character, binary and bit
strings.</p>
<p>All functions return a BIGINT value that measures the length of the
string in the given unit. CHAR_LENGTH counts characters, OCTET_LENGTH
counts octets and BIT_LENGTH counts bits in the string. For CHAR_LENGTH,
if <code class="literal">[ USING OCTETS ] </code>is specified, the octet count is
returned. (Foundation)</p>
<a name="N12D88" class="indexterm"></a>
<p>
<span class="bold"><strong>OVERLAY</strong></span>
</p>
<p>
<code class="literal">OVERLAY ( &lt;char value expr 1&gt; PLACING &lt;char value
expr 2&gt;</code>
</p>
<p>
<code class="literal">FROM &lt;start position&gt; [ FOR &lt;string length&gt; ] [
USING CHARACTERS ] )</code>
</p>
<p>
<code class="literal">OVERLAY ( &lt;binary value expr 1&gt; PLACING &lt;binary
value expr 2&gt;</code>
</p>
<p>
<code class="literal">FROM &lt;start position&gt; [ FOR &lt;string length&gt; ]
)</code>
</p>
<p>The character version of OVERLAY returns a character string based on
<code class="literal">&lt;char value expr 1&gt;</code> in which <code class="literal">&lt;string
length&gt;</code> characters have been removed from the
<code class="literal">&lt;start position&gt;</code> and in their place, the whole
<code class="literal">&lt;char value expr 2&gt;</code> is copied.</p>
<p>The binary version of OVERLAY returns a binary string formed in the
same manner as the character version. (Foundation)</p>
<a name="N12DAD" class="indexterm"></a>
<p>
<span class="bold"><strong>POSITION</strong></span>
</p>
<p>
<code class="literal">POSITION ( &lt;char value expr 1&gt; IN &lt;char value expr
2&gt; [ USING CHARACTERS ] )</code>
</p>
<p>
<code class="literal">POSITION ( &lt;binary value expr 1&gt; IN &lt;binary value
expr 2&gt; )</code>
</p>
<p>The character and binary versions of POSITION search the string
value of the second argument for the first occurrence of the first
argument string. If the search is successful, the position in the string
is returned as a BIGINT. Otherwise zero is returned.</p>
<a name="N12DBE" class="indexterm"></a>
<p>
<span class="bold"><strong>SUBSTRING</strong></span>
</p>
<p>
<code class="literal">SUBSTRING ( &lt;char value expr&gt; FROM &lt;start
position&gt; [ FOR &lt;string length&gt; ] [ USING CHARACTERS ]
)</code>
</p>
<p>
<code class="literal">SUBSTRING ( &lt;binary value expr&gt; FROM &lt;start
position&gt; [ FOR &lt;string length&gt; ] )</code>
</p>
<p>The character version of SUBSTRING returns a character string that
consists of the characters of the <code class="literal">&lt;char value expr&gt;
</code>from <code class="literal">&lt;start position&gt;</code>. If the
optional<code class="literal"> &lt;string length&gt;</code> is specified, only
<code class="literal">&lt;string length&gt; </code>characters are returned.</p>
<p>The binary version of SUBSTRING returns a binary string in the same
manner. (Foundation)</p>
<a name="N12DDD" class="indexterm"></a>
<p>
<span class="bold"><strong>TRIM</strong></span>
</p>
<p>
<code class="literal">TRIM ([ [ LEADING | TRAILING | BOTH ] [ &lt;trim
character&gt; ] FROM ] &lt;char value expr&gt; )</code>
</p>
<p>
<code class="literal">TRIM ([ [ LEADING | TRAILING | BOTH ] [ &lt;trim octet&gt;
] FROM ] &lt;binary value expr&gt; )</code>
</p>
<p>The character version of TRIM returns a character string based on
<code class="literal">&lt;char value expr&gt;</code>. Consecutive instances of
<code class="literal">&lt;trim character&gt; </code>are removed from the beginning,
the end or both ends of the<code class="literal">&lt;char value expr&gt;
</code>depending on the value of the optional first qualifier
<code class="literal">[ LEADING | TRAILING | BOTH ]</code>. If no qualifier is
specified, <code class="literal">BOTH </code>is used as default. If <code class="literal">[
&lt;trim character&gt; ]</code> is not specified, the space character
is used as default.</p>
<p>The binary version of TRIM returns a binary string based on
<code class="literal">&lt;binary value expr&gt;</code>. Consecutive instances of
<code class="literal">&lt;trim octet&gt; </code>are removed in the same manner as in
the character version. If<code class="literal"> [ &lt;trim octet&gt; ]</code> is not
specified, the 0 octet is used as default. (Foundation)</p>
</div>
<div class="section" lang="en">
<div class="titlepage">
<div>
<div>
<h2 class="title" style="clear: both">
<a name="builtin_functions_numeric-sect"></a>Numeric Functions</h2>
</div>
</div>
</div>
<a name="N12E0F" class="indexterm"></a>
<p>
<span class="bold"><strong>ABS</strong></span>
</p>
<p>
<code class="literal">ABS ( &lt;num value expr&gt; | &lt;interval value expr&gt;
) </code>
</p>
<p>Returns the absolute value of the argument as a value of the same
type. (JDBC and Foundation)</p>
<a name="N12E1D" class="indexterm"></a>
<p>
<span class="bold"><strong>ACOS</strong></span>
</p>
<p>
<code class="literal">ACOS ( &lt;num value expr&gt; ) </code>
</p>
<p>Returns the arc-cosine of the argument in radians as a value of
DOUBLE type. (JDBC)</p>
<a name="N12E2B" class="indexterm"></a>
<p>
<span class="bold"><strong>ASIN</strong></span>
</p>
<p>
<code class="literal">ASIN ( &lt;num value expr&gt; ) </code>
</p>
<p>Returns the arc-sine of the argument in radians as a value of DOUBLE
type. (JDBC)</p>
<a name="N12E39" class="indexterm"></a>
<p>
<span class="bold"><strong>ATAN</strong></span>
</p>
<p>
<code class="literal">ATAN ( &lt;num value expr&gt; ) </code>
</p>
<p>Returns the arc-tangent of the argument in radians as a value of
DOUBLE type. (JDBC)</p>
<a name="N12E47" class="indexterm"></a>
<p>
<span class="bold"><strong>ATAN2</strong></span>
</p>
<p>
<code class="literal">ATAN2 ( &lt;num value expr 1&gt;, &lt;num value expr 2&gt;
) </code>
</p>
<p>The <code class="literal">&lt;num value expr 1&gt;</code> and <code class="literal">&lt;num
value expr 2&gt;</code> express the <code class="varname">x</code> and
<code class="varname">y</code> coordinates of a point. Returns the angle, in
radians, representing the angle coordinate of the point in polar
coordinates, as a value of DOUBLE type. (JDBC)</p>
<a name="N12E61" class="indexterm"></a>
<p>
<span class="bold"><strong>CEILING</strong></span>
</p>
<p>
<code class="literal">{ CEIL | CEILING } ( &lt;num value expr&gt; )
</code>
</p>
<p>Returns the smallest integer greater than or equal to the argument.
If the argument is exact numeric then the result is exact numeric with a
scale of 0. If the argument is approximate numeric, then the result is of
DOUBLE type. (JDBC and Foundation)</p>
<a name="N12E6F" class="indexterm"></a>
<p>
<span class="bold"><strong>BITAND</strong></span>
</p>
<p>
<code class="literal">BITAND ( &lt;num value expr 1&gt;, &lt;num value expr 2&gt;
)</code>
</p>
<p>
<code class="literal">BITAND ( &lt;bit value expr 1&gt;, &lt;bit value expr 2&gt;
)</code>
</p>
<a name="N12E7E" class="indexterm"></a>
<p>
<span class="bold"><strong>BITOR</strong></span>
</p>
<p>
<code class="literal">BITOR ( &lt;num value expr 1&gt;, &lt;num value expr 2&gt;
)</code>
</p>
<p>
<code class="literal">BITOR ( &lt;bit value expr 1&gt;, &lt;bit value expr 2&gt;
)</code>
</p>
<a name="N12E8D" class="indexterm"></a>
<p>
<span class="bold"><strong>BITXOR</strong></span>
</p>
<p>
<code class="literal">BITXOR ( &lt;num value expr 1&gt;, &lt;num value expr 2&gt;
)</code>
</p>
<p>
<code class="literal">BITXOR ( &lt;bit value expr 1&gt;, &lt;bit value expr 2&gt;
)</code>
</p>
<p>These three functions perform the bit operations: OR, AND, XOR, on
two values. The values are either integer values, or bit strings. The
result is an integer value of the same type as the arguments, or a bit
string of the same length as the argument. Each bit of the result is
formed by performing the operation on corresponding bits of the arguments.
(HyperSQL)</p>
<a name="N12E9E" class="indexterm"></a>
<p>
<span class="bold"><strong>COS</strong></span>
</p>
<p>
<code class="literal">COS ( &lt;num value expr&gt; ) </code>
</p>
<p>Returns the cosine of the argument (an angle expressed in radians)
as a value of DOUBLE type. (JDBC)</p>
<a name="N12EAC" class="indexterm"></a>
<p>
<span class="bold"><strong>COT</strong></span>
</p>
<p>
<code class="literal">COT ( &lt;num value expr&gt; ) </code>
</p>
<p>Returns the cotangent of the argument as a value of DOUBLE type. The
<code class="literal">&lt;num value expr&gt;</code> represents an angle expressed in
radians. (JDBC)</p>
<a name="N12EBD" class="indexterm"></a>
<p>
<span class="bold"><strong>DEGREES</strong></span>
</p>
<p>
<code class="literal">DEGREES ( &lt;num value expr&gt; ) </code>
</p>
<p>Converts the argument (an angle expressed in<code class="literal">
radians</code>) into degrees and returns the value in the DOUBLE type.
(JDBC)</p>
<a name="N12ECE" class="indexterm"></a>
<p>
<span class="bold"><strong>EXP</strong></span>
</p>
<p>
<code class="literal">EXP ( &lt;num value expr&gt; ) </code>
</p>
<p>Returns the exponential value of the argument as a value of DOUBLE
type. (JDBC and Foundation)</p>
<a name="N12EDC" class="indexterm"></a>
<p>
<span class="bold"><strong>FLOOR</strong></span>
</p>
<p>
<code class="literal">FLOOR ( &lt;num value expr&gt; ) </code>
</p>
<p>Returns the largest integer that is less than or equal to the
argument. If the argument is exact numeric then the result is exact
numeric with a scale of 0. If the argument is approximate numeric, then
the result is of DOUBLE type. (JDBC and Foundation)</p>
<a name="N12EEA" class="indexterm"></a>
<p>
<span class="bold"><strong>LN</strong></span>
</p>
<p>
<code class="literal">LN ( &lt;num value expr&gt; ) </code>
</p>
<p>Returns the natural logarithm of the argument, as a value of DOUBLE
type. (Foundation)</p>
<a name="N12EF8" class="indexterm"></a>
<p>
<span class="bold"><strong>LOG</strong></span>
</p>
<p>
<code class="literal">LOG ( &lt;num value expr&gt; ) </code>
</p>
<p>Returns the natural logarithm of the argument, as a value of DOUBLE
type. (JDBC)</p>
<a name="N12F06" class="indexterm"></a>
<p>
<span class="bold"><strong>LOG10</strong></span>
</p>
<p>
<code class="literal">LOG10 ( &lt;num value expr&gt; ) </code>
</p>
<p>Returns the base 10 logarithm of the argument as a value of DOUBLE
type. (JDBC)</p>
<p>
<code class="literal">MOD ( &lt;num value expr 1&gt;, &lt;num value expr 2&gt; )
</code>
</p>
<a name="N12F17" class="indexterm"></a>
<p>
<span class="bold"><strong>MOD</strong></span>
</p>
<p>Returns the remainder (modulus) of <code class="literal">&lt;num value expr
1&gt;</code> divided by <code class="literal">&lt;num value expr 2&gt;.</code>
The data type of the returned value is the same as the second argument.
(JDBC and Foundation)</p>
<a name="N12F28" class="indexterm"></a>
<p>
<span class="bold"><strong>PI</strong></span>
</p>
<p>
<code class="literal">PI () </code>
</p>
<p>Returns the constant pi as a value of DOUBLE type. (JDBC)</p>
<a name="N12F36" class="indexterm"></a>
<p>
<span class="bold"><strong>POWER</strong></span>
</p>
<p>
<code class="literal">POWER ( &lt;num value expr 1&gt;, &lt;num value expr 2&gt;
) </code>
</p>
<p>Returns the value of <code class="literal">&lt;num value expr 1&gt;</code>
raised to the power of <code class="literal">&lt;int value expr 2&gt;</code> as a
value of DOUBLE type. (JDBC and Foundation)</p>
<a name="N12F4A" class="indexterm"></a>
<p>
<span class="bold"><strong>RADIANS</strong></span>
</p>
<p>
<code class="literal">RADIANS ( &lt;num value expr&gt; ) </code>
</p>
<p>Converts the argument (an angle expressed in<code class="literal">
degrees</code>) into radians and returns the value in the DOUBLE type.
(JDBC)</p>
<a name="N12F5B" class="indexterm"></a>
<p>
<span class="bold"><strong>RAND</strong></span>
</p>
<p>
<code class="literal">RAND ( [ &lt;int value expr&gt; ] ) </code>
</p>
<p>Returns a random value in the DOUBLE type. The optional <code class="literal">[
&lt;int value expr&gt; ]</code> is used as seed value. In HyperSQL each
session has a separate random number generator. The first call that uses a
seed parameter sets the seed for subsequent calls that do not include a
parameter. (JDBC)</p>
<a name="N12F6C" class="indexterm"></a>
<p>
<span class="bold"><strong>ROUND</strong></span>
</p>
<p>
<code class="literal">ROUND ( &lt;num value expr&gt;, &lt;int value expr&gt; )
</code>
</p>
<p>The <code class="literal">&lt;num value expr&gt; </code>is of the DOUBLE type.
The function returns a DOUBLE value which is the value of the argument
rounded to <code class="literal">&lt;int value expr&gt;</code> places right of the
decimal point. If <code class="literal">&lt;int value expr&gt;</code> is negative,
the first argument is rounded to <code class="literal">&lt;int value expr&gt;</code>
places to the left of the decimal point. (JDBC)</p>
<a name="N12F86" class="indexterm"></a>
<p>
<span class="bold"><strong>SIGN</strong></span>
</p>
<p>
<code class="literal">SIGN ( &lt;num value expr&gt; ) </code>
</p>
<p>Returns an INTEGER, indicating the sign of the argument. If the
argument is negative then -1 is returned. If it is equal to zero then 0 is
returned. If the argument is positive then 1 is returned. (JDBC)</p>
<a name="N12F94" class="indexterm"></a>
<p>
<span class="bold"><strong>SIN</strong></span>
</p>
<p>
<code class="literal">SIN ( &lt;num value expr&gt; ) </code>
</p>
<p>Returns the sine of the argument (an angle expressed in radians) as
a value of DOUBLE type. (JDBC)</p>
<a name="N12FA2" class="indexterm"></a>
<p>
<span class="bold"><strong>SQRT</strong></span>
</p>
<p>
<code class="literal">SQRT ( &lt;num value expr&gt; ) </code>
</p>
<p>Returns the square root of the argument as a value of DOUBLE type.
(JDBC and Foundation)</p>
<a name="N12FB0" class="indexterm"></a>
<p>
<span class="bold"><strong>TAN</strong></span>
</p>
<p>
<code class="literal">TAN ( &lt;num value expr&gt; ) </code>
</p>
<p>Returns the tangent of the argument (an angle expressed in radians)
as a value of DOUBLE type. (JDBC)</p>
<a name="N12FBE" class="indexterm"></a>
<p>
<span class="bold"><strong>TRUNCATE</strong></span>
</p>
<p>
<code class="literal">TRUNCATE ( &lt;num value expr&gt;, &lt;int value expr&gt; )
</code>
</p>
<p>Returns a value in the same type as <code class="literal">&lt;num value
expr&gt;</code>. The value is rounded by replacing digits with zeros
from <code class="literal">&lt;int value expr&gt;</code> places right of the decimal
point to the end. If <code class="literal">&lt;int value expr&gt;</code> is
negative, <code class="literal">ABS( &lt;int value expr&gt; )</code> digits to left
of the decimal point and all digits to the right of the decimal points are
replaced with zeros. Results of calling TRUNCATE with 12345.6789 with (-2,
0, 2, 4) are (12300.0000, 12345.0000, 12345.6700, 12345.6789).
(JDBC)</p>
</div>
<div class="section" lang="en">
<div class="titlepage">
<div>
<div>
<h2 class="title" style="clear: both">
<a name="builtin_functions_datetime-sect"></a>Date Time and Interval Functions</h2>
</div>
</div>
</div>
<a name="N12FDC" class="indexterm"></a>
<p>
<span class="bold"><strong>TIMEZONE</strong></span>
</p>
<p>
<code class="literal">TIMEZONE()</code>
</p>
<p>Returns the current time zone for the session. Returns an INTERVAL
HOUR TO MINUTE value. (HyperSQL)</p>
<a name="N12FEA" class="indexterm"></a>
<p>
<span class="bold"><strong>SESSION_TIMEZONE</strong></span>
</p>
<p>
<code class="literal">SESSION_TIMEZONE()</code>
</p>
<p>Returns the default time zone for the current session. Returns an
INTERVAL HOUR TO MINUTE value. (HyperSQL)</p>
<a name="N12FF8" class="indexterm"></a>
<p>
<span class="bold"><strong>DATABASE_TIMEZONE</strong></span>
</p>
<p>
<code class="literal">DATABASE_TIMEZONE()</code>
</p>
<p>Returns the time zone for the database engine. This is based on
where the database server process is located. Returns an INTERVAL HOUR TO
MINUTE value. (HyperSQL)</p>
<a name="N13006" class="indexterm"></a>
<p>
<span class="bold"><strong>EXTRACT</strong></span>
</p>
<p>
<code class="literal">EXTRACT ( &lt;extract field&gt; FROM &lt;extract source&gt;
)</code>
</p>
<p>
<code class="literal">&lt;extract field&gt; ::= YEAR | MONTH | DAY | HOUR |
MINUTE | DAY_OF_WEEK | WEEK_OF_YEAR | QUARTER | DAY_OF_YEAR | DAY_OF_MONTH
|</code>
</p>
<p>
<code class="literal">TIMEZONE_HOUR | TIMEZONE_MINUTE | SECOND |
SECONDS_SINCE_MIDNIGHT |</code>
</p>
<p>
<code class="literal">DAY_NAME | MONTH_NAME</code>
</p>
<p>
<code class="literal">&lt;extract source&gt; ::= &lt;datatime value expr&gt; |
&lt;interval value expr&gt;</code>
</p>
<p>The EXTRACT function returns a field or element of the
<code class="literal">&lt;extract source&gt;</code>. The <code class="literal">&lt;extract
source&gt;</code> is a datetime or interval expression. The type of the
return value is BIGINT for most of the<code class="literal"> &lt;extract
field&gt;</code> options. The exceptions is <code class="literal">SECOND
</code>where a DECIMAL value is returned which has the same precision
as the datetime or interval expression. The field values <code class="literal">DAY_NAME
</code>or<code class="literal"> MONTH_NAME </code>result in a character string.
When <code class="literal">MONTH_NAME</code> is specified, a string in the range
January - December is returned. When <code class="literal">DAY_NAME </code>is
specified, a string in the range Sunday -Saturday is returned.</p>
<p>If the <code class="literal">&lt;extract source&gt;</code> is <code class="literal">FROM
&lt;datatime value expr&gt;</code>, different groups of
<code class="literal">&lt;extract source&gt;</code> can be used depending on the
data type of the expression. The <code class="literal">TIMEZONE_HOUR |
TIMEZONE_MINUTE</code> options are valid only for TIME WITH TIMEZONE
and TIMESTAMP WITH TIMEZONE data types. The <code class="literal">HOUR | MINUTE |
SECOND | SECONDS_MIDNIGHT</code> options, are valid for TIME and
TIMESTAMP types. The rest of the fields are valid for DATE and TIMESTAMP
types.</p>
<p>If the <code class="literal">&lt;extract source&gt;</code> is <code class="literal">FROM
&lt;interval value expr&gt;</code>, the <code class="literal">&lt;extract
field&gt;</code> must be one of the fields of the INTERVAL type of the
expressions. The <code class="literal">YEAR | MONTH</code> options may be valid for
INTERVAL types based on months. The <code class="literal">DAY | HOUR | MINUTE | SECOND
| SECONDS_MIDNIGHT</code> options may be valid for INTERVAL types based
on seconds. For example,<code class="literal"> DAY | HOUR | MINUTE</code> are the
only valid fields for the INTERVAL DAY TO MINUTE data type. (Foundation
with HyperSQL extensions)</p>
<a name="N1305D" class="indexterm"></a>
<p>
<span class="bold"><strong>CURRENT_DATE</strong></span>
</p>
<p>
<code class="literal">CURRENT_DATE</code>
</p>
<a name="N13069" class="indexterm"></a>
<p>
<span class="bold"><strong>CURRENT_TIME</strong></span>
</p>
<p>
<code class="literal">CURRENT_TIME [ ( &lt;time precision&gt; )
]</code>
</p>
<a name="N13075" class="indexterm"></a>
<p>
<span class="bold"><strong>LOCALTIME</strong></span>
</p>
<p>
<code class="literal">LOCALTIME [ ( &lt;time precision&gt; ) ]</code>
</p>
<a name="N13081" class="indexterm"></a>
<p>
<span class="bold"><strong>CURRENT_TIMESTAMP</strong></span>
</p>
<p>
<code class="literal">CURRENT_TIMESTAMP [ ( &lt;timestamp precision&gt; )
]</code>
</p>
<a name="N1308D" class="indexterm"></a>
<p>
<span class="bold"><strong>LOCALTIMESTAMP</strong></span>
</p>
<p>
<code class="literal">LOCALTIMESTAMP [ ( &lt;timestamp precision&gt; )
]</code>
</p>
<p>These datetime functions return the datetime value representing the
moment the function is called. CURRENT_DATE returns a value of DATE type.
CURRENT_TIME returns a value of TIME WITH TIME ZONE type. LOCALTIME
returns a value of TIME type. CURRENT_TIMESTAMP returns a value of
TIMESTAMP WITH TIME ZONE type. LOCALTIMESTAMP returns a value of TIMESTAMP
type. If the optional <code class="literal">[ ( &lt;time precision&gt; ) ]</code>
or<code class="literal"> [ ( &lt;timestamp precision&gt; ) ]</code> is used, then
the returned value has the specified fraction of the second precision.
(Foundation)</p>
<a name="N130A1" class="indexterm"></a>
<p>
<span class="bold"><strong>CURDATE</strong></span>
</p>
<p>
<code class="literal">CURDATE ()</code>
</p>
<p>This function is equivalent to<code class="literal"> CURRENT_DATE.
</code>(JDBC)</p>
<a name="N130B2" class="indexterm"></a>
<p>
<span class="bold"><strong>CURTIME</strong></span>
</p>
<p>
<code class="literal">CURTIME ()</code>
</p>
<p>This function is equivalent to<code class="literal"> LOCALTIME</code>.
(JDBC)</p>
<a name="N130C3" class="indexterm"></a>
<p>
<span class="bold"><strong>DAYNAME</strong></span>
</p>
<p>
<code class="literal">DAYNAME ( &lt;datatime value expr&gt; )</code>
</p>
<p>This function is equivalent to<code class="literal"> EXTRACT ( DAY_NAME FROM ...
) </code>Returns a string in the range of Sunday - Saturday.
(JDBC)</p>
<a name="N130D4" class="indexterm"></a>
<p>
<span class="bold"><strong>DAYOFMONTH</strong></span>
</p>
<p>
<code class="literal">DAYOFMONTH ( &lt;datetime value expr&gt; )</code>
</p>
<p>This function is equivalent to<code class="literal"> EXTRACT ( DAY_OF_MONTH FROM
... ) </code>Returns an integer value in the range of 1-31.
(JDBC)</p>
<a name="N130E5" class="indexterm"></a>
<p>
<span class="bold"><strong>DAYOFWEEK</strong></span>
</p>
<p>
<code class="literal">DAYOFWEEK ( &lt;datetime value expr&gt; )</code>
</p>
<p>This function is equivalent to <code class="literal">EXTRACT ( DAY_OF_WEEK FROM
... ) </code>Returns an integer value in the range of 1-7. The first
day of the week is Sunday. (JDBC)</p>
<a name="N130F6" class="indexterm"></a>
<p>
<span class="bold"><strong>DAYOFYEAR</strong></span>
</p>
<p>
<code class="literal">DAYOFYEAR ( &lt;datetime value expr&gt; )</code>
</p>
<p>This function is equivalent to <code class="literal">EXTRACT ( DAY_OF_YEAR FROM
... ) </code>Returns an integer value in the range of 1-366.
(JDBC)</p>
<a name="N13107" class="indexterm"></a>
<p>
<span class="bold"><strong>HOUR</strong></span>
</p>
<p>
<code class="literal">HOUR ( &lt;datetime value expr&gt; )</code>
</p>
<p>This function is equivalent to <code class="literal">EXTRACT ( HOUR FROM ... )
</code>Returns an integer value in the range of 0-23. (JDBC)</p>
<a name="N13118" class="indexterm"></a>
<p>
<span class="bold"><strong>MINUTE</strong></span>
</p>
<p>
<code class="literal">MINUTE ( &lt;datetime value expr&gt; )</code>
</p>
<p>This function is equivalent to<code class="literal"> EXTRACT ( MINUTE FROM ... )
</code>Returns an integer value in the range of 0 - 59. (JDBC)</p>
<a name="N13129" class="indexterm"></a>
<p>
<span class="bold"><strong>MONTH</strong></span>
</p>
<p>
<code class="literal">MONTH ( &lt;datetime value expr&gt; )</code>
</p>
<p>This function is equivalent to <code class="literal">EXTRACT ( MONTH FROM ... )
</code>Returns an integer value in the range of 1-12. (JDBC)</p>
<a name="N1313A" class="indexterm"></a>
<p>
<span class="bold"><strong>MONTHNAME</strong></span>
</p>
<p>
<code class="literal">MONTHNAME ( &lt;datetime value expr&gt; )</code>
</p>
<p>This function is equivalent to <code class="literal">EXTRACT ( NAME_OF_MONTH FROM
... ) </code>Returns a string in the range of January - December.
(JDBC)</p>
<a name="N1314B" class="indexterm"></a>
<p>
<span class="bold"><strong>NOW</strong></span>
</p>
<p>
<code class="literal">NOW ()</code>
</p>
<p>This function is equivalent to
<code class="literal">LOCAL_TIMESTAMP.</code>
</p>
<a name="N1315B" class="indexterm"></a>
<p>
<span class="bold"><strong>QUARTER</strong></span>
</p>
<p>
<code class="literal">QUARTER ( &lt;datetime value expr&gt; )</code>
</p>
<p>This function is equivalent to <code class="literal">EXTRACT ( QUARTER FROM ... )
</code>Returns an integer in the range of 1 - 4. (JDBC)</p>
<a name="N1316C" class="indexterm"></a>
<p>
<span class="bold"><strong>SECOND</strong></span>
</p>
<p>
<code class="literal">SECOND ( &lt;datetime value expr&gt; )</code>
</p>
<p>This function is equivalent to <code class="literal">EXTRACT ( SECOND FROM ... )
</code>Returns an integer or decimal in the range of 0 - 59, with the
same precision as the &lt;datetime value expr&gt;. (JDBC)</p>
<a name="N1317D" class="indexterm"></a>
<p>
<span class="bold"><strong>SECONDS_SINCE_MIDNIGHT</strong></span>
</p>
<p>
<code class="literal">SECONDS_SINCE_MIDNIGHT ( &lt;datetime value expr&gt;
)</code>
</p>
<p>This function is equivalent to<code class="literal"> EXTRACT (
SECONDS_SINCE_MIDNIGHT FROM ... ) </code>Returns an integer in the
range of 0 - 86399. (HyperSQL)</p>
<a name="N1318E" class="indexterm"></a>
<p>
<span class="bold"><strong>WEEK</strong></span>
</p>
<p>
<code class="literal">WEEK ( &lt;datetime value expr&gt; )</code>
</p>
<p>This function is equivalent to<code class="literal"> EXTRACT ( WEEK_OF_YEAR FROM
... ) </code>Returns an integer in the range of 1 - 54. (JDBC)</p>
<a name="N1319F" class="indexterm"></a>
<p>
<span class="bold"><strong>YEAR</strong></span>
</p>
<p>
<code class="literal">YEAR ( &lt;datetime value expr&gt; )</code>
</p>
<p>This function is equivalent to<code class="literal"> EXTRACT ( YEAR FROM ... )
</code>Returns an integer in the range of 1 - 9999. (JDBC)</p>
<a name="N131B0" class="indexterm"></a>
<p>
<span class="bold"><strong>TIMESTAMPADD</strong></span>
</p>
<p>
<code class="literal">TIMESTAMPADD ( &lt;tsi datetime field&gt;, &lt;numeric
value expression&gt;, &lt;datetime value expr&gt;)</code>
</p>
<a name="N131BC" class="indexterm"></a>
<p>
<span class="bold"><strong>TIMESTAMPDIFF</strong></span>
</p>
<p>
<code class="literal">TIMESTAMPDIFF ( &lt;tsi datetime field&gt;, &lt;datetime
value expr 1&gt;, &lt;datetime value expr 2&gt;)</code>
</p>
<p>
<code class="literal">&lt;tsi datetime field&gt; ::= SQL_TSI_FRAC_SECOND |
SQL_TSI_SECOND | SQL_TSI_MINUTE | SQL_TSI_HOUR | SQL_TSI_DAY |
SQL_TSI_WEEK | SQL_TSI_MONTH | SQL_TSI_QUARTER |
SQL_TSI_YEAR</code>
</p>
<p>HyperSQL supports full SQL Standard datetime features. It supports
adding integers representing units of time directly to datetime values
using the arithmetic plus operator. It also supports subtracting one
<code class="literal">&lt;datetime value expr&gt;</code> from another in the given
units of days using the minus operator. An example of
<code class="literal">&lt;datetime value expr&gt; + &lt;numeric value expression&gt;
&lt;datetime field&gt; </code>is <code class="literal">LOCAL_TIMESTAMP + 5
DAY</code>. An example of <code class="literal">( &lt;datetime value expr&gt; -
&lt;numeric value expression&gt; ) &lt;datetime field&gt; </code>is
<code class="literal">(CURRENT_DATE - DATE '2008-08-8') MONTH </code>which returns
the number of calendar months between the two dates.</p>
<p>The two JDBC functions, <code class="literal">TIMESTAMPADD </code>and
<code class="literal">TIMESTAMPDIFF</code> perform the same function as above SQL
expressions. The field names are keywords and are different from those
used in the EXTRACT functions. These names are valid for use only when
calling these two functions. The return value for TIMESTAMPADD is of the
same type as the datetime argument used. The return type for TIMESTAMPDIFF
is always BIGINT, regardless of the type of arguments. The two datetime
arguments of TIMESTAMPDIFF should be of the same type. (JDBC)</p>
<a name="N131E4" class="indexterm"></a>
<p>
<span class="bold"><strong>DATEADD</strong></span>
</p>
<p>
<code class="literal">DATEADD ( &lt;field&gt;, &lt;numeric value expr&gt;,
&lt;datetime value expr&gt; )</code>
</p>
<a name="N131F0" class="indexterm"></a>
<p>
<span class="bold"><strong>DATEDIFF</strong></span>
</p>
<p>
<code class="literal">DATEDIFF ( &lt;field&gt;, &lt;datetime value expr 1&gt;,
datetime value expr 2&gt; )</code>
</p>
<p>
<code class="literal">&lt;field&gt; ::= 'yy' | 'mm' | 'dd' | 'hh' | 'mi' | 'ss' |
'ms'</code>
</p>
<p>The DATEADD and DATEDIFF functions are alternatives to TIMESTAMPADD
and TIMESTAMPDIFF, with fewer available field options. The field names are
specified as strings, rather than keywords. The fields translate to YEAR,
MONTH, DAY, HOUR, MINUTE, SECOND and MILLISECOND. (HyperSQL}</p>
<a name="N13201" class="indexterm"></a>
<p>
<span class="bold"><strong>TO_CHAR</strong></span>
</p>
<p>
<code class="literal">TO_CHAR( &lt;datetime value expr&gt;, &lt;char value
expr&gt; )</code>
</p>
<p>This function formats a datetime or numeric value to the format
specified by the pattern given in the second argument. The pattern can
contain pattern elements from the list given below, plus punctuation and
space characters. An example, including the result, is given below:</p>
<pre class="programlisting">TO_CHAR ( TIMESTAMP'2008-02-01 20:30:40', 'YYYY BC MONTH, DAY HH')
2008 AD February, Friday 8
</pre>
<p>The format is internally translated to a
<code class="classname">java.text.SimpleDateFormat</code> format string. Any
character sequences not listed below are included in the Java format
string and may cause unexpected results or errors. Therefore unsupported
format strings should not be used. The supported format components are as
follows:</p>
<div class="table">
<a name="N13216"></a>
<p class="title">
<b>Table&nbsp;10.1.&nbsp;TO CHAR Values</b>
</p>
<div class="table-contents">
<table summary="TO CHAR Values" cellspacing="0" style="border-collapse: collapse;border-top: 0.5pt solid ; border-bottom: 0.5pt solid ; border-left: 0.5pt solid ; border-right: 0.5pt solid ; ">
<colgroup>
<col>
<col>
</colgroup>
<tbody>
<tr>
<td style="border-right: 0.5pt solid ; border-bottom: 0.5pt solid ; "><code class="literal">BC | B.C. | AD | A.D.</code></td><td style="border-bottom: 0.5pt solid ; ">Returns <code class="literal">AD</code> for common era and
<code class="literal">BC</code> for before common era</td>
</tr>
<tr>
<td style="border-right: 0.5pt solid ; border-bottom: 0.5pt solid ; "><code class="literal">RRRR</code></td><td style="border-bottom: 0.5pt solid ; ">
<p>4-digit year</p>
</td>
</tr>
<tr>
<td style="border-right: 0.5pt solid ; border-bottom: 0.5pt solid ; "><code class="literal">YYYY</code></td><td style="border-bottom: 0.5pt solid ; ">
<p>4-digit year</p>
</td>
</tr>
<tr>
<td style="border-right: 0.5pt solid ; border-bottom: 0.5pt solid ; "><code class="literal">IYYY</code></td><td style="border-bottom: 0.5pt solid ; ">
<p>4-digit year</p>
</td>
</tr>
<tr>
<td style="border-right: 0.5pt solid ; border-bottom: 0.5pt solid ; "><code class="literal">YY</code></td><td style="border-bottom: 0.5pt solid ; ">
<p>2 digit year</p>
</td>
</tr>
<tr>
<td style="border-right: 0.5pt solid ; border-bottom: 0.5pt solid ; "><code class="literal">IY</code></td><td style="border-bottom: 0.5pt solid ; ">
<p>2 digit year</p>
</td>
</tr>
<tr>
<td style="border-right: 0.5pt solid ; border-bottom: 0.5pt solid ; "><code class="literal">IYYY</code></td><td style="border-bottom: 0.5pt solid ; ">
<p>4-digit year</p>
</td>
</tr>
<tr>
<td style="border-right: 0.5pt solid ; border-bottom: 0.5pt solid ; "><code class="literal">MM</code></td><td style="border-bottom: 0.5pt solid ; ">
<p>Month (01-12)</p>
</td>
</tr>
<tr>
<td style="border-right: 0.5pt solid ; border-bottom: 0.5pt solid ; "><code class="literal">MON</code></td><td style="border-bottom: 0.5pt solid ; ">
<p>Short three-letter name of month</p>
</td>
</tr>
<tr>
<td style="border-right: 0.5pt solid ; border-bottom: 0.5pt solid ; "><code class="literal">MONTH</code></td><td style="border-bottom: 0.5pt solid ; ">
<p>Name of month</p>
</td>
</tr>
<tr>
<td style="border-right: 0.5pt solid ; border-bottom: 0.5pt solid ; "><code class="literal">WW</code></td><td style="border-bottom: 0.5pt solid ; ">
<p>Week of year (1-53) where week 1 starts on the first
day of the year and continues to the seventh day of the
year.</p>
</td>
</tr>
<tr>
<td style="border-right: 0.5pt solid ; border-bottom: 0.5pt solid ; "><code class="literal">W</code></td><td style="border-bottom: 0.5pt solid ; ">
<p>Week of month (1-5) where week 1 starts on the first
day of the month and ends on the seventh.</p>
</td>
</tr>
<tr>
<td style="border-right: 0.5pt solid ; border-bottom: 0.5pt solid ; "><code class="literal">IW</code></td><td style="border-bottom: 0.5pt solid ; ">
<p>Week of year (1-52 or 1-53) based on the ISO
standard.</p>
</td>
</tr>
<tr>
<td style="border-right: 0.5pt solid ; border-bottom: 0.5pt solid ; "><code class="literal">DAY</code></td><td style="border-bottom: 0.5pt solid ; ">
<p>Name of day.</p>
</td>
</tr>
<tr>
<td style="border-right: 0.5pt solid ; border-bottom: 0.5pt solid ; "><code class="literal">DD</code></td><td style="border-bottom: 0.5pt solid ; ">
<p>Day of month (1-31).</p>
</td>
</tr>
<tr>
<td style="border-right: 0.5pt solid ; border-bottom: 0.5pt solid ; "><code class="literal">DDD</code></td><td style="border-bottom: 0.5pt solid ; ">
<p>Day of year (1-366).</p>
</td>
</tr>
<tr>
<td style="border-right: 0.5pt solid ; border-bottom: 0.5pt solid ; "><code class="literal">DY</code></td><td style="border-bottom: 0.5pt solid ; ">
<p>Short three-letter name of day.</p>
</td>
</tr>
<tr>
<td style="border-right: 0.5pt solid ; border-bottom: 0.5pt solid ; "><code class="literal">HH</code></td><td style="border-bottom: 0.5pt solid ; ">
<p>Hour of day (0-11).</p>
</td>
</tr>
<tr>
<td style="border-right: 0.5pt solid ; border-bottom: 0.5pt solid ; "><code class="literal">HH12</code></td><td style="border-bottom: 0.5pt solid ; ">
<p>Hour of day (0-11).</p>
</td>
</tr>
<tr>
<td style="border-right: 0.5pt solid ; border-bottom: 0.5pt solid ; "><code class="literal">HH24</code></td><td style="border-bottom: 0.5pt solid ; ">
<p>Hour of day (0-23).</p>
</td>
</tr>
<tr>
<td style="border-right: 0.5pt solid ; border-bottom: 0.5pt solid ; "><code class="literal">MI</code></td><td style="border-bottom: 0.5pt solid ; ">
<p>Minute (0-59).</p>
</td>
</tr>
<tr>
<td style="border-right: 0.5pt solid ; border-bottom: 0.5pt solid ; "><code class="literal">SS</code></td><td style="border-bottom: 0.5pt solid ; ">
<p>Second (0-59).</p>
</td>
</tr>
<tr>
<td style="border-right: 0.5pt solid ; "><code class="literal">FF</code></td><td style="">
<p>Fractional seconds.</p>
</td>
</tr>
</tbody>
</table>
</div>
</div>
<br class="table-break">
</div>
<div class="section" lang="en">
<div class="titlepage">
<div>
<div>
<h2 class="title" style="clear: both">
<a name="N132C8"></a>Array Functions</h2>
</div>
</div>
</div>
<p>Array functions are specialised functions with ARRAY
parameters.</p>
<a name="N132CD" class="indexterm"></a>
<p>
<span class="bold"><strong>CARDINALITY</strong></span>
</p>
<p>
<code class="literal">CARDINALITY( &lt;array value expr&gt; )</code>
</p>
<p>Returns the element count for the given array argument.
(Foundation)</p>
<a name="N132DB" class="indexterm"></a>
<p>
<span class="bold"><strong>MAX_CARDINALITY</strong></span>
</p>
<p>
<code class="literal">MAX_CARDINALITY( &lt;array value expr&gt;
)</code>
</p>
<p>Returns the maximum allowed element count for the given array
argument. (Foundation)</p>
<a name="N132E9" class="indexterm"></a>
<p>
<span class="bold"><strong>TRIM_ARRAY</strong></span>
</p>
<p>
<code class="literal">TRIM_ARRAY( &lt;array value expr&gt;, &lt;num value
expr&gt; )</code>
</p>
<p>Returns a new array that contains the elements of the
<code class="literal">&lt;array value expr&gt;</code> minus the number of elements
specified by the <code class="literal">&lt;num value expr&gt;. </code>Elements are
discarded from the end of the array. (Foundation)</p>
</div>
<div class="section" lang="en">
<div class="titlepage">
<div>
<div>
<h2 class="title" style="clear: both">
<a name="N132FD"></a>General Functions</h2>
</div>
</div>
</div>
<p>General functions can take different types of arguments. Some
General Functions accept a variable number of arguments.</p>
<a name="N13302" class="indexterm"></a>
<p>
<span class="bold"><strong>COALESCE</strong></span>
</p>
<p>
<code class="literal">COALESCE( &lt;value expr 1&gt;, &lt;value expr 2&gt; [,
...] )</code>
</p>
<p>Returns <code class="literal">&lt;value expr 1&gt;</code> if it is not null,
otherwise returns <code class="literal">&lt;value expr 2&gt;</code> if not null and
so on. The type of both arguments must be comparable. (Foundation)</p>
<a name="N13316" class="indexterm"></a>
<p>
<span class="bold"><strong>CONVERT</strong></span>
</p>
<p>
<code class="literal">CONVERT ( &lt;value expr&gt; , &lt;data type&gt;
)</code>
</p>
<p>
<code class="literal">&lt;data type&gt; ::= { SQL_BIGINT | SQL_BINARY | SQL_BIT
|SQL_BLOB | SQL_BOOLEAN | SQL_CHAR | SQL_CLOB | SQL_DATE | SQL_DECIMAL |
SQL_DATALINK |SQL_DOUBLE | SQL_FLOAT | SQL_INTEGER | SQL_LONGVARBINARY |
SQL_LONGNVARCHAR | SQL_LONGVARCHAR | SQL_NCHAR | SQL_NCLOB | SQL_NUMERIC |
SQL_NVARCHAR | SQL_REAL | SQL_ROWID | SQL_SQLXML | SQL_SMALLINT | SQL_TIME
| SQL_TIMESTAMP | SQL_TINYINT | SQL_VARBINARY | SQL_VARCHAR} [ (
&lt;precision, length or scale parameters&gt; ) ]</code>
</p>
<p>The CONVERT function is a JDBC escape function, equivalent to the
SQL standard CAST expression. It converts the <code class="literal">&lt;value
expr&gt;</code> into the given <code class="literal">&lt;data type&gt;</code> and
returns the value. The <code class="literal">&lt;data type&gt;</code> options are
synthetic names made by prefixing type names with <code class="literal">SQL_</code>.
Some of the <code class="literal">&lt;data type&gt;</code> options represent valid
SQL types, but some are based on non-standard type names, namely
<code class="literal">{ SQL_LONGNVARCHAR | SQL_LONGVARBINARY |SQL_LONGVARCHAR |
SQL_TINYINT }</code>. None of the synthetic names can be used in any
other context than the CONVERT function.</p>
<p>The definition of CONVERT in the JDBC Standard does not allow the
precision, scale or length to be specified. This is required by the SQL
standard for BINARY, BIT, BLOB, CHAR, CLOB, VARBINARY and VARCHAR types
and is often needed for DECIMAL and NUMERIC. Therefore, HyperSQL allows
the use of precision, scale or length for the type definition when they
are valid for the type definition. HyperSQL also allows the use of real
type names (without the <code class="literal">SQL_</code> prefix). (JDBC)</p>
<a name="N1333E" class="indexterm"></a>
<p>
<span class="bold"><strong>DECODE</strong></span>
</p>
<p>
<code class="literal">DECODE( &lt;value expr main&gt;, &lt;value expr match
1&gt;, &lt;value expr result 1&gt; [...,] [, &lt;value expr default&gt;]
)</code>
</p>
<p>DECODE takes at least 3 arguments. The <code class="literal">&lt;value expr
main&gt;</code> is compared with <code class="literal">&lt;value expr match
1&gt;</code> and if it matches, <code class="literal">&lt;value expr result
1&gt;</code> is returned. If there are additional pairs of
<code class="literal">&lt;value expr match n&gt;</code> and <code class="literal">&lt;value expr
result n&gt;</code>, comparison is repeated until a match is found the
result is returned. If no match is found, the <code class="literal">&lt;value expr
default&gt;</code> is returned if it is specified, otherwise NULL is
returned. The type of the return value is a combination of the types of
the <code class="literal">&lt;value expr result ... &gt;</code> arguments.
(HyperSQL)</p>
<a name="N13361" class="indexterm"></a>
<p>
<span class="bold"><strong>GREATEST</strong></span>
</p>
<p>
<code class="literal">GREATEST( &lt;value expr 1&gt;, [&lt;value expr ...&gt;,
...] )</code>
</p>
<p>The GREATEST function takes one or more arguments. It compares the
arguments with each other and returns the greatest argument. The return
type is the combined type of the arguments. Arguments can be of any type,
so long as they are comparable. (HyperSQL)</p>
<a name="N1336F" class="indexterm"></a>
<p>
<span class="bold"><strong>IFNULL</strong></span>
</p>
<p>
<code class="literal">IFNULL( &lt;value expr 1&gt;, &lt;value expr 2&gt;
)</code>
</p>
<p>Returns <code class="literal">&lt;value expr 1&gt;</code> if it is not null,
otherwise returns <code class="literal">&lt;value expr 2&gt;</code>. The type of
both arguments must be the same. Equivalent to SQL Standard
<code class="literal">COALESCE(&lt;value expr 1&gt;, &lt;value expr 2&gt;)</code>
function. (JDBC)</p>
<a name="N13386" class="indexterm"></a>
<p>
<span class="bold"><strong>LEAST</strong></span>
</p>
<p>
<code class="literal">LEAST( &lt;value expr 1&gt;, [&lt;value expr ...&gt;, ...]
)</code>
</p>
<p>The LEAST function takes one or more arguments. It compares the
arguments with each other and returns the smallest argument. The return
type is the combined type of the arguments. Arguments can be of any type,
so long as they are comparable. (HyperSQL)</p>
<a name="N13394" class="indexterm"></a>
<p>
<span class="bold"><strong>NULLIF</strong></span>
</p>
<p>
<code class="literal">NULLIF( &lt;value expr 1&gt;, &lt;value expr 2&gt;
)</code>
</p>
<p>Returns <code class="literal">&lt;value expr 1&gt;</code> if it is not equal
to <code class="literal">&lt;value expr 2&gt;</code>, otherwise returns null. The
type of both arguments must be the same. This function is a shorthand for
a specific CASE expression. (Foundation)</p>
<a name="N133A8" class="indexterm"></a>
<p>
<span class="bold"><strong>NVL</strong></span>
</p>
<p>
<code class="literal">NVL( &lt;value expr 1&gt;, &lt;value expr 2&gt;
)</code>
</p>
<p>Returns <code class="literal">&lt;value expr 1&gt;</code> if it is not null,
otherwise returns <code class="literal">&lt;value expr 2&gt;</code>. The type of the
return value is the combined type of the two value expressions. For
example, if &lt;value expr 1&gt; is an INTEGER column and
<code class="literal">&lt;value expr 2&gt;</code> is a DOUBLE constant, the return
type is DOUBLE. This function is the same as IFNULL and COALESCE
(HyperSQL)</p>
</div>
<div class="section" lang="en">
<div class="titlepage">
<div>
<div>
<h2 class="title" style="clear: both">
<a name="builtin_functions_sysfunc-sect"></a>System Functions</h2>
</div>
</div>
</div>
<a name="N133C3" class="indexterm"></a>
<p>
<span class="bold"><strong>CRYPT_KEY</strong></span>
</p>
<p>
<code class="literal">CRYPT_KEY( &lt;value expr 1&gt;, &lt;value expr 2&gt;
)</code>
</p>
<p>Returns a binary string representation of a cryptography key for the
given cipher and cyptography provider. The cipher specification is
specified by <code class="literal">&lt;value expr 1&gt;</code> and the provider by
<code class="literal">&lt;value expr 2&gt;</code>. To use the default provider,
specify null for <code class="literal">&lt;value expr 2&gt;</code>.
(HyperSQL)</p>
<a name="N133DA" class="indexterm"></a>
<p>
<span class="bold"><strong>IDENTITY</strong></span>
</p>
<p>
<code class="literal">IDENTITY ()</code>
</p>
<p>Returns the last IDENTITY value inserted into a row by the current
session. The statement, CALL IDENTITY() can be made after an INSERT
statement that inserts a row into a table with an IDENTITY column. The
CALL IDENTITY() statement returns the last IDENTITY value that was
inserted into a table by the current session. Each session manages this
function call separately and is not affected by inserts in other sessions.
The statement can be executed as a direct statement or a prepared
statement. (HyperSQL)</p>
<a name="N133E8" class="indexterm"></a>
<p>
<span class="bold"><strong>DATABASE</strong></span>
</p>
<p>
<code class="literal">DATABASE ()</code>
</p>
<p>Returns the file name (without directory information) of the
database. (JDBC)</p>
<a name="N133F6" class="indexterm"></a>
<p>
<span class="bold"><strong>DATABASE_VERSION</strong></span>
</p>
<p>
<code class="literal">DATABASE_VERSION ()</code>
</p>
<p>Returns the full version string for the database engine. For
example, 2.0.1. (JDBC)</p>
<a name="N13404" class="indexterm"></a>
<p>
<span class="bold"><strong>USER</strong></span>
</p>
<p>
<code class="literal">USER ()</code>
</p>
<p>Equivalent to the SQL function <code class="literal">CURRENT_USER</code>.
(JDBC)</p>
<a name="N13415" class="indexterm"></a>
<p>
<span class="bold"><strong>CURRENT_USER</strong></span>
</p>
<p>
<code class="literal">CURRENT_USER</code>
</p>
<a name="N13421" class="indexterm"></a>
<p>
<span class="bold"><strong>CURRENT_ROLE</strong></span>
</p>
<p>
<code class="literal">CURRENT_ROLE</code>
</p>
<a name="N1342D" class="indexterm"></a>
<p>
<span class="bold"><strong>SESSION_USER</strong></span>
</p>
<p>
<code class="literal">SESSION_USER</code>
</p>
<a name="N13439" class="indexterm"></a>
<p>
<span class="bold"><strong>SYSTEM_USER</strong></span>
</p>
<p>
<code class="literal">SYSTEM_USER</code>
</p>
<a name="N13445" class="indexterm"></a>
<p>
<span class="bold"><strong>CURRENT_SCHEMA</strong></span>
</p>
<p>
<code class="literal">CURRENT_SCHEMA</code>
</p>
<a name="N13451" class="indexterm"></a>
<p>
<span class="bold"><strong>CURRENT_CATALOG</strong></span>
</p>
<p>
<code class="literal">CURRENT_CATALOG</code>
</p>
<p>These functions return the named current session attribute. They are
all SQL Standard functions.</p>
<p>The CURRENT_USER is the user that connected to the database, or a
user subsequently set by the SET AUTHORIZATION statement.</p>
<p>SESSION_USER is the same as CURRENT_USER</p>
<p>SYSTEM_USER is the user that connected to the database. It is not
changed with any command until the session is closed.</p>
<p>CURRENT_SCHEMA is default schema of the user, or a schema
subsequently set by the SET SCHEMA command.</p>
<p>CURRENT_CATALOG is always the same within a given HyperSQL database
and indicates the name of the catalog.</p>
<a name="N13469" class="indexterm"></a>
<p>
<span class="bold"><strong>ISAUTOCOMMIT</strong></span>
</p>
<p>
<code class="literal">ISAUTOCOMMIT()</code>
</p>
<p>Returns TRUE if the session is in autocommit mode. (HyperSQL)</p>
<a name="N13477" class="indexterm"></a>
<p>
<span class="bold"><strong>ISREADONLYSESSION</strong></span>
</p>
<p>
<code class="literal">ISREADONLYSESSION()</code>
</p>
<p>Returns TRUE if the session is in read only mode. (HyperSQL)</p>
<a name="N13485" class="indexterm"></a>
<p>
<span class="bold"><strong>ISREADONLYDATABASE</strong></span>
</p>
<p>
<code class="literal">ISREADONLYDATABASE()</code>
</p>
<p>Returns TRUE if the database is a read only database.
(HyperSQL)</p>
<a name="N13493" class="indexterm"></a>
<p>
<span class="bold"><strong>ISREADONLYDATABASEFILES</strong></span>
</p>
<p>
<code class="literal">ISREADONLYDATABASEFILES()</code>
</p>
<p>Returns TRUE if the database is a read-only files database. In this
kind of database, it is possible to modify the data, but the changes are
not persisted to the database files. (HyperSQL)</p>
<a name="N134A1" class="indexterm"></a>
<p>
<span class="bold"><strong>ISOLATION_LEVEL</strong></span>
</p>
<p>
<code class="literal">ISOLATION_LEVEL()</code>
</p>
<p>Returns the current transaction isolation level for the session.
Returns either READ COMMITTED or SERIALIZABLE as a string.
(HyperSQL)</p>
<a name="N134AF" class="indexterm"></a>
<p>
<span class="bold"><strong>SESSION_ISOLATION_LEVEL</strong></span>
</p>
<p>
<code class="literal">SESSION_ISOLATION_LEVEL()</code>
</p>
<p>Returns the default transaction isolation level for the current
session. Returns either READ COMMITTED or SERIALIZABLE as a string.
(HyperSQL)</p>
<a name="N134BD" class="indexterm"></a>
<p>
<span class="bold"><strong>DATABASE_ISOLATION_LEVEL</strong></span>
</p>
<p>
<code class="literal">DATABASE_ISOLATION_LEVEL()</code>
</p>
<p>Returns the default transaction isolation level for the database.
Returns either READ COMMITTED or SERIALIZABLE as a string.
(HyperSQL)</p>
<a name="N134CB" class="indexterm"></a>
<p>
<span class="bold"><strong>TRANSACTION_CONTROL</strong></span>
</p>
<p>
<code class="literal">TRANSACTION_CONTROL()</code>
</p>
<p>Returns the current transaction model for the database. Returns
LOCKS, MVLOCKS or MVCC as a string. (HyperSQL)</p>
</div>
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