Re: Sequences

hi hunter, <br />  <p>nextval increments the sequence in an atomic operation and returns the current value <br />of
thesequence.  It is transaction safe in the sense, <p>if two webserver process do two transactions simultaneously they
wouldstill get different <br />current vals. <p>so last_val should not be the approach. <p>forgive me if i am not
understanding the intricacies of your <br />problem. <br />  <br />  <p>"Hunter, Ray" wrote: <blockquote type="CITE"> 
<p><fontsize="-1">The only problem with this solution is that I have already incremented the sequence and need to use
thecurrent value?  Is there a way to assign the value to a variable and then use it in an insert
statement?</font><p><fontsize="-1">This is just a hashed out example.  I am hoping it can all be done in sql
statements...</font><br/><font size="-1">Example:</font><br />        <font size="-1">var num = select last_value from
user_table_id_seq;</font><p>       <font size="-1">insert into users ( "user_id", "user_fname", "user_lname",
"user_email")</font><br /><font size="-1">        values ( 'num', 'Ray', 'Hunter', 'rhunter@enterasys.com'
);</font><p><fontsize="-1">If I could do this is would be great...Is it possible?</font><p><font
size="-1">Thanks,</font><br/>  <br />  <p><font size="-1">Ray Hunter</font><br /><font size="-1">Firmware
Engineer</font><p><fontsize="-1">ENTERASYS NETWORKS</font><p><font size="-1">-----Original Message-----</font><br
/><fontsize="-1">From: Bruno Wolff III [<a href="mailto:bruno@wolff.to">mailto:bruno@wolff.to</a>]</font><br /><font
size="-1">Sent:Monday, February 11, 2002 7:37 AM</font><br /><font size="-1">To: Hunter, Ray</font><br /><font
size="-1">Cc:pgsql-sql@postgresql.org</font><br /><font size="-1">Subject: Re: [SQL] Sequences</font><p><font
size="-1">OnMon, Feb 11, 2002 at 08:43:23AM -0500,</font><br /><font size="-1">  "Hunter, Ray"
<rhunter@enterasys.com>wrote:</font><br /><font size="-1">> I have various sequences in my database set up for
ids. My question</font><br /><font size="-1">> is: How can I get the current value of the sequence without creating
a</font><br/><font size="-1">> session and using the currval function?</font><br /><font size="-1">></font><br
/><fontsize="-1">> I would like to take the current value of the sequence and use it for</font><br /><font
size="-1">>a value in an insert statement.</font><br /><font size="-1">></font><br /><font
size="-1">></font><br/><font size="-1">> Example:</font><br /><font size="-1">></font><br /><font
size="-1">>      insert into users ( "user_id", "user_fname", "user_lname",</font><br /><font size="-1">>
"user_email")</font><br /><font size="-1">>       values ( 'current sequence', 'Ray', 'Hunter',
'rhunter@enterasys.com'</font><br/><font size="-1">> );</font><p><font size="-1">I think you want to use nextval in
thiscontext. currval is used when you have already gotten a new sequence number and want to use it in several inserts
inthe same transaction.</font><p><font size="-1">If you make user_id a serial type, then its default value will be
nextvaland you could use: insert into users ( "user_fname", "user_lname", "user_email" )</font><p><font size="-1"> 
values('Ray', 'Hunter', 'rhunter@enterasys.com' );</font><br /><font size="-1">to add a row.</font></blockquote>