How to implement a 1-n relationship

Question

I'm using oracle 8.1 and currently learning JDO.
Havin the following schema :
DROP TABLE permission_group_map CASCADE CONSTRAINTS;
CREATE TABLE permission_group_map (
permission_group_map_oid NUMBER(10) NOT NULL,
version_oid NUMBER(3) NOT NULL,
group_oid NUMBER(10) NOT NULL,
permission_oid NUMBER(10) NOT NULL,
jdolock NUMBER NULL,
user_id VARCHAR2(20) NULL,
timestamp DATE NULL
ALTER TABLE permission_group_map
ADD ( CONSTRAINT PKpermission_group_map PRIMARY KEY (
permission_group_map_oid) ) ;
DROP TABLE permission CASCADE CONSTRAINTS;
CREATE TABLE permission (
permission_oid NUMBER(10) NOT NULL,
version_oid NUMBER(3) NOT NULL,
name VARCHAR2(60) NULL,
visibility NUMBER(1) NULL,
jdolock NUMBER NULL,
user_id VARCHAR2(20) NULL,
timestamp DATE NULL
ALTER TABLE permission
ADD ( CONSTRAINT PKpermission PRIMARY KEY (permission_oid,
version_oid) ) ;
DROP TABLE user_group CASCADE CONSTRAINTS;
CREATE TABLE user_group (
group_oid NUMBER(10) NOT NULL,
name VARCHAR2(60) NULL,
jdolock NUMBER NULL,
user_id VARCHAR2(20) NULL,
timestamp DATE NULL
ALTER TABLE user_group
ADD ( CONSTRAINT PKuser_group PRIMARY KEY (group_oid) ) ;
ALTER TABLE permission_group_map
ADD ( CONSTRAINT fk2_permission_group_map
FOREIGN KEY (group_oid)
REFERENCES user_group ) ;
ALTER TABLE permission_group_map
ADD ( CONSTRAINT fk1_permission_group_map
FOREIGN KEY (permission_oid, version_oid)
REFERENCES permission ) ;
How can represent a 1-n relation in a .jdo file without adding more fileds.
Here is my .jdo implementation
<class identity-type="application" name="UserGroup"
objectid-class="UserGroupKey" requires-extent="false">
<extension key="table" value="USER_GROUP" vendor-name="kodo"/>
<field name="name" null-value="exception" primary-key="false">
<extension key="data-column" value="NAME"
vendor-name="kodo"/>
<extension key="column-length" value="60"
vendor-name="kodo"/>
</field>
<field name="userId" null-value="exception"
primary-key="false">
<extension key="data-column" value="USER_ID"
vendor-name="kodo"/>
</field>
<field name="groupOid" null-value="exception"
primary-key="true">
<extension key="data-column" value="GROUP_OID"
vendor-name="kodo"/>
</field>
<field name="timestamp" null-value="exception"
primary-key="false">
<extension key="data-column" value="TIMESTAMP"
vendor-name="kodo"/>
</field>
<field name = "permissionGroupMap">
<collection element-type="PermissionGroupMap"/>
<extension vendor-name="kodo" key="inverse"
value="userGroup"/>
</field>
<extension key="lock-column" value="jdolock"
vendor-name="kodo"/>
<extension key="class-column" value="none" vendor-name="kodo"/>
</class>
<class identity-type="application" name="PermissionGroupMap"
objectid-class="PermissionGroupMapKey" requires-extent="false">
<extension key="table" value="PERMISSION_GROUP_MAP"
vendor-name="kodo"/>
<extension key="lock-column" value="jdolock"
vendor-name="kodo"/>
<extension key="class-column" value="none" vendor-name="kodo"/>
<field name="permissionGroupMapOid" null-value="exception"
primary-key="true">
<extension key="data-column"
value="PERMISSION_GROUP_MAP_OID" vendor-name="kodo"/>
</field>
<field name="userId" null-value="exception"
primary-key="false">
<extension key="data-column" value="USER_ID"
vendor-name="kodo"/>
</field>
<field name="permissionOid" null-value="exception"
primary-key="false">
<extension key="data-column" value="PERMISSION_OID"
vendor-name="kodo"/>
</field>
<field name="groupOid" null-value="exception"
primary-key="false">
<extension key="data-column" value="GROUP_OID"
vendor-name="kodo"/>
</field>
<field name="versionOid" null-value="exception"
primary-key="false">
<extension key="data-column" value="VERSION_OID"
vendor-name="kodo"/>
</field>
<field name="timestamp" null-value="exception"
primary-key="false">
<extension key="data-column" value="TIMESTAMP"
vendor-name="kodo"/>
</field>
</class>
and here is the class code
public class PermissionGroupMap {
java.math.BigDecimal permissionGroupMapOid;
java.lang.String userId;
java.math.BigDecimal permissionOid;
java.math.BigDecimal groupOid;
java.math.BigDecimal versionOid;
java.util.Date timestamp;
/** relationship fields **/
UserGroup userGroup;
public class UserGroup {
java.lang.String name;
java.lang.String userId;
java.math.BigDecimal groupOid;
java.util.Date timestamp;
/** relationship fields **/
ArrayList permissionGroupMap = new ArrayList();
Here is the exception that I'm getting :
javax.jdo.JDODataStoreException: [SQL=SELECT t0.PERMISSION_GROUP_MAP_OID,
t0.jdolock, t0.GROUP_OID, t0.PERMISSION_OID, t0.TIMESTAMP,
t0.GROUPOID_USERGROUPX, t0.USER_ID, t0.VERSION_OID FROM
PERMISSION_GROUP_MAP t0 WHERE t0.GROUPOID_USERGROUPX = 1] ORA-00904:
invalid column name

Answer 1

Thanks for you quick response, But I changed the schema a little bit, just
to play arround, now I'm doing a m-n, but it does not work, can you tell
me what I'm doing wrong, here is the schema :
CREATE TABLE user_group (
group_oid NUMBER(10) NOT NULL,
name VARCHAR2(60) NULL,
jdolock NUMBER NULL,
user_id VARCHAR2(20) NULL,
timestamp DATE NULL,
CONSTRAINT PKuser_group
PRIMARY KEY (group_oid)
CREATE TABLE permission (
permission_oid NUMBER(10) NOT NULL,
version_oid NUMBER(3) NOT NULL,
name VARCHAR2(60) NULL,
visibility NUMBER(1) NULL,
jdolock NUMBER NULL,
user_id VARCHAR2(20) NULL,
timestamp DATE NULL,
CONSTRAINT PKpermission
PRIMARY KEY (permission_oid, version_oid)
CREATE TABLE permission_group_map (
group_oid NUMBER(10) NOT NULL,
permission_oid NUMBER(10) NOT NULL,
version_oid NUMBER(3) NOT NULL,
CONSTRAINT PKpermission_group_map
PRIMARY KEY (group_oid, permission_oid, version_oid),
CONSTRAINT R_4
FOREIGN KEY (permission_oid, version_oid)
REFERENCES permission,
CONSTRAINT R_3
FOREIGN KEY (group_oid)
REFERENCES user_group
the .jod file :
<class identity-type="application" name="Permission"
objectid-class="PermissionKey" requires-extent="false">
<extension key="table" value="PERMISSION" vendor-name="kodo"/>
<field name="permissionOid" null-value="exception"
persistence-modifier="persistent" primary-key="true">
<extension key="data-column" value="PERMISSION_OID"
vendor-name="kodo"/>
<extension key="column-length" value="10"
vendor-name="kodo"/>
<extension key="column-index" value="pkPermission"
vendor-name="kodo"/>
</field>
<field name="versionOid" null-value="exception"
persistence-modifier="persistent" primary-key="true">
<extension key="data-column" value="VERSION_OID"
vendor-name="kodo"/>
<extension key="column-index" value="pkPermission"
vendor-name="kodo"/>
<extension key="column-length" value="3"
vendor-name="kodo"/>
</field>
<field name="userGroups">
<collection element-type="UserGroup"/>
<extension vendor-name="kodo" value="permissions"/>
<extension vendor-name="kodo" key="table"
value="PERMISSION_GROUP_MAP"/>
<extension vendor-name="kodo" key="groupOid-data-column"
value="GROUP_OID"/>
<extension vendor-name="kodo"
key="permissionOid-ref-column" value="PERMISSION_OID"/>
<extension vendor-name="kodo" key="versionOid-ref-column"
value="VERSION_OID"/>
</field>
<extension key="class-column" value="none" vendor-name="kodo"/>
<extension key="lock-column" value="jdolock"
vendor-name="kodo"/>
</class>
<class identity-type="application" name="UserGroup"
objectid-class="UserGroupKey" requires-extent="false">
<extension key="table" value="USER_GROUP" vendor-name="kodo"/>
<field name="name" null-value="exception" primary-key="false">
<extension key="data-column" value="NAME"
vendor-name="kodo"/>
<extension key="column-length" value="60"
vendor-name="kodo"/>
</field>
<field name="permissions">
<extension vendor-name="kodo" value="userGroups"/>
<extension vendor-name="kodo" key="table"
value="PERMISSION_GROUP_MAP"/>
<extension vendor-name="kodo" key="groupOid-ref-column"
value="GROUP_OID"/>
<extension vendor-name="kodo"
key="permissionOid-data-column" value="PERMISSION_OID"/>
<extension vendor-name="kodo" key="versionOid-data-column"
value="VERSION_OID"/>
</field>
<extension key="lock-column" value="jdolock"
vendor-name="kodo"/>
<extension key="class-column" value="none" vendor-name="kodo"/>
</class>
CODE :
public class Permission {
     java.math.BigDecimal visibility;
     java.lang.String name;
     java.lang.String userId;
     java.math.BigDecimal permissionOid;
     java.math.BigDecimal versionOid;
     java.util.Date timestamp;
private Collection userGroups = new ArrayList();
public class UserGroup {
     java.lang.String name;
     java.lang.String userId;
     java.math.BigDecimal groupOid;
     java.util.Date timestamp;
Collection permissions = new ArrayList();
Patrick Linskey wrote:
Manuel,
When mapping relations to pre-defined schemas using application identity,
you must use the '<fieldname>-data-column' extension syntax discussed in
http://www.solarmetric.com/Software/Documentation/2.2.6/manual.html#metadata
_extensions.
Additionally, in general, you should not have foreign key fields declared in
your java code as well as relations to other objects. For example, in
PermissionGroupMap, you should just have a relation to UserGroup, and no
groupOid field -- the foreign key information will be handled by JDO, and
should not be user-accessible except through the UserGroup relation.
So, something like this is probably more like what you want (I've removed
some fields for brevity):
<class identity-type="application" name="UserGroup"
objectid-class="UserGroupKey" requires-extent="false">
<field name="groupOid" null-value="exception" primary-key="true">
<extension key="data-column" value="GROUP_OID"
vendor-name="kodo"/>
</field>
<field name = "permissionGroupMap">
<collection element-type="PermissionGroupMap"/>
<extension vendor-name="kodo" key="inverse" value="userGroup"/>
</field>
</class>
<class identity-type="application" name="PermissionGroupMap"
objectid-class="PermissionGroupMapKey" requires-extent="false">
<field name="permissionGroupMapOid" null-value="exception"
primary-key="true">
<extension key="data-column" value="PERMISSION_GROUP_MAP_OID"
vendor-name="kodo"/>
</field>
<field name="userGroup" null-value="exception" primary-key="false">
<extension key="groupOid-data-column" value="GROUP_OID"
vendor-name="kodo"/>
</field>
</class>
public class PermissionGroupMap {
java.math.BigDecimal permissionGroupMapOid;
// this is not needed: java.math.BigDecimal groupOid;
/** relationship fields **/
UserGroup userGroup;
public class UserGroup {
java.math.BigDecimal groupOid;
/** relationship fields **/
ArrayList permissionGroupMap = new ArrayList();
On 6/8/02 11:56 AM, "Manuel Ledesma" <[email protected]> wrote:
I'm using oracle 8.1 and currently learning JDO.
Havin the following schema :
DROP TABLE permission_group_map CASCADE CONSTRAINTS;
CREATE TABLE permission_group_map (
permission_group_map_oid NUMBER(10) NOT NULL,
version_oid NUMBER(3) NOT NULL,
group_oid NUMBER(10) NOT NULL,
permission_oid NUMBER(10) NOT NULL,
jdolock NUMBER NULL,
user_id VARCHAR2(20) NULL,
timestamp DATE NULL
ALTER TABLE permission_group_map
ADD ( CONSTRAINT PKpermission_group_map PRIMARY KEY (
permission_group_map_oid) ) ;
DROP TABLE permission CASCADE CONSTRAINTS;
CREATE TABLE permission (
permission_oid NUMBER(10) NOT NULL,
version_oid NUMBER(3) NOT NULL,
name VARCHAR2(60) NULL,
visibility NUMBER(1) NULL,
jdolock NUMBER NULL,
user_id VARCHAR2(20) NULL,
timestamp DATE NULL
ALTER TABLE permission
ADD ( CONSTRAINT PKpermission PRIMARY KEY (permission_oid,
version_oid) ) ;
DROP TABLE user_group CASCADE CONSTRAINTS;
CREATE TABLE user_group (
group_oid NUMBER(10) NOT NULL,
name VARCHAR2(60) NULL,
jdolock NUMBER NULL,
user_id VARCHAR2(20) NULL,
timestamp DATE NULL
ALTER TABLE user_group
ADD ( CONSTRAINT PKuser_group PRIMARY KEY (group_oid) ) ;
ALTER TABLE permission_group_map
ADD ( CONSTRAINT fk2_permission_group_map
FOREIGN KEY (group_oid)
REFERENCES user_group ) ;
ALTER TABLE permission_group_map
ADD ( CONSTRAINT fk1_permission_group_map
FOREIGN KEY (permission_oid, version_oid)
REFERENCES permission ) ;
How can represent a 1-n relation in a .jdo file without adding more fileds.
Here is my .jdo implementation
<class identity-type="application" name="UserGroup"
objectid-class="UserGroupKey" requires-extent="false">
<extension key="table" value="USER_GROUP" vendor-name="kodo"/>
<field name="name" null-value="exception" primary-key="false">
<extension key="data-column" value="NAME"
vendor-name="kodo"/>
<extension key="column-length" value="60"
vendor-name="kodo"/>
</field>
<field name="userId" null-value="exception"
primary-key="false">
<extension key="data-column" value="USER_ID"
vendor-name="kodo"/>
</field>
<field name="groupOid" null-value="exception"
primary-key="true">
<extension key="data-column" value="GROUP_OID"
vendor-name="kodo"/>
</field>
<field name="timestamp" null-value="exception"
primary-key="false">
<extension key="data-column" value="TIMESTAMP"
vendor-name="kodo"/>
</field>
<field name = "permissionGroupMap">
<collection element-type="PermissionGroupMap"/>
<extension vendor-name="kodo" key="inverse"
value="userGroup"/>
</field>
<extension key="lock-column" value="jdolock"
vendor-name="kodo"/>
<extension key="class-column" value="none" vendor-name="kodo"/>
</class>
<class identity-type="application" name="PermissionGroupMap"
objectid-class="PermissionGroupMapKey" requires-extent="false">
<extension key="table" value="PERMISSION_GROUP_MAP"
vendor-name="kodo"/>
<extension key="lock-column" value="jdolock"
vendor-name="kodo"/>
<extension key="class-column" value="none" vendor-name="kodo"/>
<field name="permissionGroupMapOid" null-value="exception"
primary-key="true">
<extension key="data-column"
value="PERMISSION_GROUP_MAP_OID" vendor-name="kodo"/>
</field>
<field name="userId" null-value="exception"
primary-key="false">
<extension key="data-column" value="USER_ID"
vendor-name="kodo"/>
</field>
<field name="permissionOid" null-value="exception"
primary-key="false">
<extension key="data-column" value="PERMISSION_OID"
vendor-name="kodo"/>
</field>
<field name="groupOid" null-value="exception"
primary-key="false">
<extension key="data-column" value="GROUP_OID"
vendor-name="kodo"/>
</field>
<field name="versionOid" null-value="exception"
primary-key="false">
<extension key="data-column" value="VERSION_OID"
vendor-name="kodo"/>
</field>
<field name="timestamp" null-value="exception"
primary-key="false">
<extension key="data-column" value="TIMESTAMP"
vendor-name="kodo"/>
</field>
</class>
and here is the class code
public class PermissionGroupMap {
java.math.BigDecimal permissionGroupMapOid;
java.lang.String userId;
java.math.BigDecimal permissionOid;
java.math.BigDecimal groupOid;
java.math.BigDecimal versionOid;
java.util.Date timestamp;
/** relationship fields **/
UserGroup userGroup;
public class UserGroup {
java.lang.String name;
java.lang.String userId;
java.math.BigDecimal groupOid;
java.util.Date timestamp;
/** relationship fields **/
ArrayList permissionGroupMap = new ArrayList();
Here is the exception that I'm getting :
javax.jdo.JDODataStoreException: [SQL=SELECT t0.PERMISSION_GROUP_MAP_OID,
t0.jdolock, t0.GROUP_OID, t0.PERMISSION_OID, t0.TIMESTAMP,
t0.GROUPOID_USERGROUPX, t0.USER_ID, t0.VERSION_OID FROM
PERMISSION_GROUP_MAP t0 WHERE t0.GROUPOID_USERGROUPX = 1] ORA-00904:
invalid column name
Patrick Linskey [email protected]
SolarMetric Inc. http://www.solarmetric.com