Matt,
I use generated IDs a lot in my applications. My implementation looks
something like the following:
create table X
(
x_id int generated always as identity (start with 1000),
...
constraint x_pk primary key (x_id)
);
In order to get access to the generated ID, my code looks something like the
following:
ConnectionFactory connFactory = ConnectionFactory.getInstance();
conn = connFactory.getConnection();
stmt = conn.prepareStatement(insertQuery,
PreparedStatement.RETURN_GENERATED_KEYS);
... // set prepared statement parameters
stmt.executeUpdate();
// get id from the database
ResultSet rs = stmt.getGeneratedKeys();
if (rs.next())
{
int xId = rs.getInt(1);
...
}
_________________________________________
John I. Moore, Jr.
SoftMoore Consulting
email: [email protected]
web: www.softmoore.com
cell: 843-906-7887
From: [email protected] [mailto:[email protected]]
Sent: Monday, October 01, 2012 9:27 AM
To: [email protected]
Subject: Using Identity Columns with or without Sequences derby 10.8.1.2
Hi,
I'd like to use an identity-column And I am not quite sure how to receive the
used number, if I used
default.
Actually I need the particular identity-value for the entries of other tables,
since they are
supposed to reference it.
Am I forced to give those identities for my own like with a sequence-number, or
can I somwhow get it
by some "magic" statement?
--------------------------------
here my particular case:
CREATE TABLE "APP"."INPUTFILES"
(
INPUTFILE_ID int generated always as
identity
,"NAME" VARCHAR(512) NOT NULL
,"TMPST_IN" TIMESTAMP NOT NULL DEFAULT
CURRENT_TIMESTAMP
);
CREATE TABLE "APP"."OUTPUTFILES"
(
OUTPUTFILE_ID int generated always as identity
,INPUTFILE_ID int
,"NAME" VARCHAR(512) NOT NULL
,"TMPST_IN" TIMESTAMP NOT NULL DEFAULT
CURRENT_TIMESTAMP
);
ALTER TABLE "APP"."INPUTFILES" ADD CONSTRAINT "PK_INPUTFILE_ID" PRIMARY KEY
("INPUTFILE_ID");
ALTER TABLE "APP"."OUTPUTFILES" ADD CONSTRAINT "PK_OUTPUTFILE_ID" PRIMARY KEY
("OUTPUTFILE_ID");
ALTER TABLE "APP"."OUTPUTFILES" ADD CONSTRAINT "FK_INPUTFILE_ID" FOREIGN KEY
("INPUTFILE_ID")
REFERENCES "APP"."INPUTFILES" ("INPUTFILE_ID") ON DELETE CASCADE ON UPDATE
RESTRICT;
---------------
Am I right that I need to use generated by default as identity instead of int
generated always as
identity
And that there is no way to get the identity value if generated by derby?
Malte Kempff
