It is best to set the column to auto-increment and put the unique constraint
on it. Which programming language are you using?
If JAVA, the mm.mysql driver has a method that does what you want:
org.gjt.mm.mysql.Statement stmt =
(org.gjt.mm.mysql.Statement)con.createStatement();
int Results = stmt.executeUpdate(sql);
applicantID = stmt.getLastInsertID();
applicant.setApplicantID((int)applicantID);
If PERL, dbi will return the row # you just inserted using:
$statement_handle->{insertid}
If PHP, This returns the ID number used for the last INSERT statement:
$id_num = mysql_insert_id();
If C, Returns the last number generated for an AUTO_INCREMENT field:
id = mysql_insert_id(&mysql);
printf("The new ID is %d\n", id);
When using an ORACLE database, I generally use a sequence generator. I first
make a call to get the next number in the sequence, then use that number as
the key for my insert.
--Jay Gardner
-----Original Message-----
From: Jay Gardner [mailto:[EMAIL PROTECTED]]
Sent: Sunday, April 07, 2002 12:02 AM
To: Tomcat Users List
Subject: RE: saving object
What database are you using?
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]
Sent: Saturday, April 06, 2002 9:15 PM
To: Tomcat Users List
Subject: Re: saving object
I have done this with some row_id defined to be auto-insert on mysql.
With auto-insert you know it will be unique but might want to make
that a constraint.
insert .....blah blah
select max(row_id) - yields the number of the last tx.
row_id is just an example for your purpses.
Good luck
At 01:41 PM 4/5/02, you wrote:
>a little bit off topic.
>
>I have a table with each row corresponds to a javabean object. The objects
>don't
>necessarily have a primary key, so i use a sequence number as its primary
>key, and a
>trigger to assign the sequence number to its ID column when a new object is
>inserted
>into the database.
>
>However, after I insert the object into the table, how can i know the
>object's ID in the
>table? If I simply do a "..._seq.cur_val", it is not safe when multiple
>users can access
>the database and save their javabean into it at the same time.
>
>How could you guys accomplish that?
>
>
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