Each column has the option to have a identity column which automatically
increases a counter if a row is inserted.
.. here a section of a JUnit test of mine using this ..
...
Statement s = _connection.createStatement();
/*
We create a table, add a few rows, and update one.
*/
s.execute("create table "+testTable1+"(seq bigint not null
generated always as identity (start with 1, increment by 1), dummy
varchar(1))");
System.out.println("Created table "+testTable1);
s.execute("insert into "+testTable1+" (dummy) values('a')");
s.execute("delete from "+testTable1+" where dummy='a'");
System.out.println("Inserted to "+testTable1);
String skey = stringQuery(_connection,"values
IDENTITY_VAL_LOCAL()");
System.out.println("Derby: created DUAL: "+skey);
...
The IDENTITY_VAL_LOCAL gives you the latest number assigned
About the concept of a global seaquence generate please vote for
http://issues.apache.org/jira/browse/DERBY-103
Bernd
> -----Original Message-----
> From: Mag Gam [mailto:[EMAIL PROTECTED]
> Sent: Saturday, September 17, 2005 8:38 AM
> To: Derby Discussion
> Subject: Re: can derby have a "sequence" column?
>
> how do you get the last serial used in a table?
>
>
>
>
> On 9/16/05, Jean T. Anderson <[EMAIL PROTECTED]> wrote:
>
> firstname lastname wrote:
> > If I remember correctly, Oracle can define a column as being a
> > "sequence", which is a garaunteed unique integer for
> each record. Can
> > derby do this? A create table example would be nice.
>
> Derby supports generated "identity" columns; examples are here:
>
> http://db.apache.org/derby/docs/10.1/ref/rrefsqlj37836.html
>
> regards,
>
> -jean
>
>
>
>
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