Using entity commands in jbosscmp-jdbc.xml, can I auto generate a primary key without modifying my tables' sql create statement or the app itself? Stated another way: Does JBoss/MySQL offer a service, independent of my specific app, that will auto generate a unique value for use as a primary key?
I'm using jboss-3.2.1_tomcat-4.1.24 and MySQL 4.0.14.
Could one of these examples be modified somehow to answer the above question?
1)
This auto-increment technique doesn't quite meet the challenge. Notice that the INNODB attribute "auto_increment" has been used on column "id".
<ejb-name>CustomerEJB</ejb-name>
<table-name>CUSTOMER</table-name>
<cmp-field>
<field-name>id</field-name>
<column-name>ID</column-name>
<auto-increment/>
</cmp-field>
<entity-command name="mysql-get-generated-keys"/>
CREATE TABLE `customer` (
`id` int(10) unsigned NOT NULL auto_increment,
PRIMARY KEY (`id`)
) TYPE=InnoDB;
2)
The auto-increment sql (see tag entity-command) in this example is for the PostgreSQL database. Is there a similar sql statement for use with MySQL? Notice that the create statement was not modified to auto generate the primary key.
<ejb-name>AccountEJB</ejb-name>
<table-name>AccountEJBTable</table-name>
<unknown-pk>
<unknown-pk-class>java.lang.Long</unknown-pk-class>
<field-name>__PMPrimaryKey</field-name>
<column-name>__PMPrimaryKey</column-name>
<jdbc-type>BIGINT</jdbc-type>
<sql-type>BIGINT</sql-type>
</unknown-pk>
<entity-command name="pk-sql">
SELECT nextval('generalSEQ')
<!-- SELECT nextval('accountSEQ') -->
</entity-command>
CREATE TABLE AccountEJBTable (
__PMPrimaryKey BIGINT,
_contactInfo___PMPrimaryKey BIGINT,
_creditCard___PMPrimaryKey BIGINT,
status VARCHAR(255),
CONSTRAINT pk_AccountEJBTabl PRIMARY KEY (__PMPrimaryKey));
Finally, these techniques seem centered around pk's gen'd in sequence. What if I just want a guid generated, does that change the problem at all?
Regards,
Will
