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<TITLE>"CREATE(SEQUENCE") manual page</TITLE>
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<A HREF="sql.html">SQL Reference Contents</A>
<H2><A NAME="sect0" HREF="#toc0">NAME </A></H2>
create sequence - create a new sequence number generator
<H2><A NAME="sect1" HREF="#toc1">SYNOPSIS
</A></H2>
<B>create sequence </B> seqname <BR>
<tt> </tt><tt> </tt>[<B>increment </B> incby_value] <BR>
<tt> </tt><tt> </tt>[<B>minvalue </B> min_value]
<BR>
<tt> </tt><tt> </tt>[<B>maxvalue </B> max_value] <BR>
<tt> </tt><tt> </tt>[<B>start </B> start_value] <BR>
<tt> </tt><tt> </tt>[<B>cache </B> cache_value]
<BR>
<tt> </tt><tt> </tt>[<B>cycle </B>] <BR>
<H2><A NAME="sect2" HREF="#toc2">DESCRIPTION </A></H2>
<B>Create sequence</B> will enter a new sequence number
generator into the current data base. Actually, new single block <B>table</B>
with name <I>seqname</I> will be created and initialized. The generator will
be `owned' by the user issuing the command. <P>
The <B>increment</B> is optional clause.
Positive value will make ascending sequence, negative - descending. Default
value is 1. <P>
The optional integer <B>minvalue</B> determines the minimum value
a sequence can be. Defaults are 1/-2147483647 for ascending/descending sequences.
<P>
Use optional integer <B>maxvalue</B> to determine the maximum value for sequence.
Defaults are 2147483647/-1 for ascending/descending sequences. <P>
The optinal
<B>start</B> value enables sequence to begin anywhere. Default is <B>minvalue</B> for
ascending sequences and <B>maxvalue</B> for descending ones. <P>
The <B>cache</B> option
enables sequence numbers to be preallocated and stored in memory for
faster access. The minimum value is 1 (i.e. - no cache) and it is default.
<B>NOTE:</B> each backend uses own cache to store allocated numbers. Cached but
not used in current session numbers will be lost. <P>
The optional <B>cycle</B> keyword
may be used to enable sequence to continue when the <B>maxvalue/minvalue</B>
has been reached by ascending/descending sequence. If the limit is reached,
the next number generated will be whatever the <B>minvalue/maxvalue</B> is.
<P>
After sequence created, You may use function <B>nextval</B> with sequence name
as argument to get new number from sequence specified. Function <B>currval</B>
('sequence_name') may be used to determine number returned by last call
to <B>nextval</B> for specified sequence in current session. <P>
Use query like <BR>
<P>
select * from <sequence_name>; <BR>
<P>
to get parameters of a sequence. <BR>
<P>
Low-level
locking is used to enable multiple simultaneous calls to a generator. <P>
<H2><A NAME="sect3" HREF="#toc3">EXAMPLES </A></H2>
-- <BR>
-- Create sequence seq caching 2 numbers, starting with 10 <BR>
--
<BR>
create sequence seq cache 2 start 10; <BR>
-- <BR>
-- Select next number from sequence
<BR>
-- <BR>
select nextval ('seq'); <BR>
-- <BR>
-- Use sequence in insert <BR>
-- <BR>
insert into table
_table_ values (nextval ('seq'),...); <BR>
<H2><A NAME="sect4" HREF="#toc4">SEE ALSO </A></H2>
drop <A HREF="sequence.l.html">sequence(l)</A>
. <P>
<HR><P>
<A NAME="toc"><B>Table of Contents</B></A><P>
<UL>
<LI><A NAME="toc0" HREF="#sect0">NAME</A></LI>
<LI><A NAME="toc1" HREF="#sect1">SYNOPSIS</A></LI>
<LI><A NAME="toc2" HREF="#sect2">DESCRIPTION</A></LI>
<LI><A NAME="toc3" HREF="#sect3">EXAMPLES</A></LI>
<LI><A NAME="toc4" HREF="#sect4">SEE ALSO</A></LI>
</UL>
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