Ormlite - change name of foreign key column - ormlite

Is it possible to specify the name of the foreign key in OrmLite?
I have two tables
public class Order extends BaseData
{
#DatabaseField(id = true)
private Long order_ID;
...
#ForeignCollectionField(eager = true, maxEagerForeignCollectionLevel = 2)
private ForeignCollection<Vehicle> vehicleList;
}
public class Vehicle extends BaseData
{
#DatabaseField(id = true)
private long vehicle_ID;
...
#DatabaseField(canBeNull = false, foreign = true)
private Order order;
}
What I'd really like to do is include in the definition of my Vehicle class an order_id and then specify that ormlite uses this order_id as the foreign key field.
I've tried the below:
public class Vehicle extends BaseData
{
#DatabaseField(id = true)
private long vehicle_ID;
#DatabaseField
private long order_ID;
#DatabaseField(canBeNull = false, foreign = true, columnName = "order_ID")
private Order order;
}
However this gives error messages regarding duplicate columns when creating the database.

This question looks like one of my old answer : In ormlite, How can I have a foriegn field and a field column?.
It give you error because you creating 2 tables with the same name.
You shouldn't store the id in the database and put a setter. If you store the id in the database you will have duplicate information in. Just do :
public class Vehicle extends BaseData
{
#DatabaseField(id = true)
private long vehicle_ID;
private long order_ID;
#DatabaseField(canBeNull = false, foreign = true, columnName = "order_ID")
private Order order;
public void setOrder(Order order){
this.order=order;
order_ID = order.getId();
}
}

Related

Cannot delete or update a parent row: a foreign key constraint fails Spring JPA

I have this query
DELETE
FROM bookings as b
WHERE b.check_out = CURRENT_DATE;
and I get
Cannot delete or update a parent row: a foreign key constraint fails (online_booking_app.booked_rooms, CONSTRAINT FK3x1lpikb2vk75nx41lxhdicvn FOREIGN KEY (booking_id) REFERENCES bookings (id))
My Booking entity has CascadeType.ALL and mapped by matches the other side - from my research these are some of the mistakes that could lead to this message.
Here is the BookingEntity:
#Entity
#Table(name = "bookings")
public class BookingEntity extends BaseEntity {
#OneToMany(mappedBy = "booking",cascade = CascadeType.ALL, orphanRemoval = true)
private List<BookedRoomsEntity> bookedRooms = new ArrayList<>();
private String firstName;
private String lastName;
public List<BookedRoomsEntity> getBookedRooms() {
return bookedRooms;
}
public BookingEntity setBookedRooms(List<BookedRoomsEntity> bookedRooms) {
this.bookedRooms = bookedRooms;
return this;
}
BookedRoomsEntity
#Entity
#Table(name = "booked_rooms")
public class BookedRoomsEntity extends BaseEntity {
#ManyToOne()
private BookingEntity booking;
public BookingEntity getBooking() {
return booking;
}
public BookedRoomsEntity setBooking(BookingEntity booking) {
this.booking = booking;
return this;
}
The CascadeType does only apply to EntityManager operations.
You therefore have two options:
Load the entities to be deleted first and then use EntityManager.remove
Remove the referencing entities first with a separate JPQL statement.

Generated Key looks wrong when ManyToOne and OneToMany

I have two entities with a relationship, UserEntity:
#Embeddable
public class UserId extends EntityId implements Serializable {
#Column( length = CCEntity.ID_MAX_SIZE, name = ccIdCN )
private String ccId;
#Column( length = NAME_MAX_SIZE, name = userIdCN )
private String userId;
...
}
#Entity
#Table(name = TableNames.CC_Users)
public class UserEntity {
#EmbeddedId
private UserId id;
...
#OneToMany(targetEntity = ProfileEntity.class, mappedBy = "user", fetch = FetchType.EAGER, cascade = { CascadeType.PERSIST, CascadeType.REFRESH, CascadeType.MERGE })
private List<ProfileEntity> profiles;
And the ProfileEntity:
#Embeddable
public class ProfileId extends EntityId implements Serializable {
#Column( length = CCEntity.ID_MAX_SIZE, name = ccIdCN )
private String ccId;
#Column( length = NAME_MAX_SIZE, name = profileIdCN )
private String profileId;
....
}
#Entity
#Table(name = TableNames.CC_Profile)
public class ProfileEntity {
#EmbeddedId
protected ProfileId id;
...
#ManyToOne
#JoinColumns(value = {
#JoinColumn( nullable = true, name = Columns.referenceIdCN, referencedColumnName = UserId.userIdCN ),
#JoinColumn( nullable = true, name = Columns.ccIdOfReferenceCN, referencedColumnName = UserId.ccIdCN ),
})
private UserEntity user;
When JPA creates the tables it generates the following:
Table CC_USER with primary key: cc_id, user_id. That is correct.
Table CC_PROFILE with primary key: cc_id, user_id, profile_id. Here I don't understand why JPA adds the user_id column as primary key. The table also has the columns: reference_id and cc_id_of_reference_id set as nullable.
I want property user of the ProfileEntity is optional, or nullable. If I try to add an entity with the user as null, I get :
Internal Exception: org.postgresql.util.PSQLException: ERROR: null
value in column "user_id" violates not-null constraint
thanks for any help
Finally I found the issue. I have another Entity with same TableName as ProfileEntity, but a different id. That id contains the user_id column that wasn't expected.

Hibernate Filter being ignored

My application uses Hibernate 5.02 and Wildfly 10 with a PostgreSQL 9.5 database. I'm trying to enable a filter on a #OneToMany collection held within an entity that is constructed via a NamedQuery. Unfortunately, it seems as if the filter is just ignored. Here are the different components, redacted for ease of reading.
#NamedNativeQueries({
#NamedNativeQuery(
name = "getAnalystProcess",
query = "SELECT * FROM analysis.analystprocess WHERE id = :processId",
resultClass = AnalystProcessEntity.class
)})
#FilterDef(
name = "analystProcessUnanalyzedMsgsFilter",
parameters = { #ParamDef(name = "processIds", type = "integer"), #ParamDef(name = "analystIds", type = "integer") })
#Filter(name = "analystProcessUnanalyzedMsgsFilter", condition = "analystprocess_id IN (:processIds) AND id NOT IN (SELECT msg_id FROM analysis.analyzedmsg WHERE analyst_id IN (:analystIds) AND analystprocess_id IN (:processIds)) ORDER BY process_msg_id")
#Entity
#Table(name = "analystprocess", schema = "analyst")
public class AnalystProcessEntity implements JPAEntity {
public static final String GET_PROCESS = "getAnalystProcess";
public static final String MSG_FILTER = "analystProcessUnanalyzedMsgsFilter";
public static final String MSG_FILTER_PROC_ID_PARAM = "processIds";
public static final String MSG_FILTER_ANALYST_ID_PARAM = "analystIds";
private static final long serialVersionUID = 1L;
...
#OneToMany(fetch = FetchType.LAZY, orphanRemoval = true, mappedBy = "process")
#OrderColumn(name = "process_msg_id")
#LazyCollection(LazyCollectionOption.EXTRA)
private List<MsgEntity> msgList;
#Entity
#Table(name = "msg", schema = "analyst")
public class MsgEntity implements JPAEntity {
...
#ManyToOne(cascade = CascadeType.ALL, optional = false)
#JoinColumn(name = "analystprocess_id", referencedColumnName = "id")
private AnalystProcessEntity process;
#Column(name = "process_msg_id")
private Integer processMsgId;
private void buildAnalystProcess() {
LOG.info("Building AnalystProcessEntity");
analystUser.getJdbcSession().enableFilter(AnalystProcessEntity.MSG_FILTER)
.setParameter(AnalystProcessEntity.MSG_FILTER_PROC_ID_PARAM, analystProcessId)
.setParameter(AnalystProcessEntity.MSG_FILTER_ANALYST_ID_PARAM, analystUser.getId());
Query query = analystUser.getJdbcSession().getNamedQuery(AnalystProcessEntity.GET_PROCESS)
.setParameter("processId", analystProcessId);
// Query query = analystUser.getJdbcSession().createNativeQuery("SELECT * FROM analysis.analystprocess WHERE id = :processId")
// .setParameter("processId", analystProcessId)
// .addEntity(AnalystProcessEntity.class);
analystProcess = (AnalystProcessEntity) query.getSingleResult();
CREATE TABLE analysis.analystprocess (
id SERIAL PRIMARY KEY,
name TEXT NOT NULL UNIQUE,
description TEXT,
created_date TIMESTAMP NOT NULL DEFAULT now(),
...
);
CREATE TABLE analysis.msg (
id SERIAL PRIMARY KEY,
analystprocess_id INTEGER NOT NULL REFERENCES analysis.analystprocess(id) ON DELETE CASCADE ON UPDATE CASCADE,
process_msg_id INTEGER NOT NULL,
constraint tbl_statusid_analystprocessid unique(status_id, analystprocess_id)
);
As seen above, I have also tried the filter on constructing the AnalystProcessEntity class via createNativeQuery instead of getNamedQuery and no luck.
I also added a defaultCondition with hardcoded values into the #FilterDef just to see if it would execute the default condition and it still didn't.
I've tried the #Filter above the entity definition as well as above the class definition. I even came across a blog post which made it sound like the condition references entity fields (variable names) and not table fields (column names). Trying to stick to Java naming conventions in the Entity and Postgres naming conventions in the table, so I tried switching the references in the condition and to no avail.
I have sql logging turned on in Hibernate and the condition doesn't show up anywhere, as if it's just simply being ignored.
Any help would be greatly appreciated!
So, the problem was that I had the #FilterDef applied to the wrong class. It was my presumption that because I was constructing the AnalystProcessEntity which holds the MsgEntity collection (which I am trying to filter), that the #FilterDef would be applied to the AnalystProcessEntity class. Instead, it needs to be applied to the entity that it's actually filtering (hindsight being 20/20, that's pretty obvious).
Also, the actual condition needed to be modified to use complete references within the sub-select query.
I hope this helps someone at some point...
#NamedNativeQueries({
#NamedNativeQuery(
name = "getAnalystProcess",
query = "SELECT * FROM analysis.analystprocess WHERE id = :processId",
resultClass = AnalystProcessEntity.class
)})
#Filter(name = "analystProcessUnanalyzedMsgsFilter", condition = "id NOT IN (SELECT amsg.msg_id FROM analysis.analyzedmsg amsg WHERE amsg.analyst_id IN (:analystIds) AND amsg.analystprocess_id IN (:processIds))")
#Entity
#Table(name = "analystprocess", schema = "analyst")
public class AnalystProcessEntity implements JPAEntity {
public static final String GET_PROCESS = "getAnalystProcess";
public static final String MSG_FILTER = "analystProcessUnanalyzedMsgsFilter";
public static final String MSG_FILTER_PROC_ID_PARAM = "processIds";
public static final String MSG_FILTER_ANALYST_ID_PARAM = "analystIds";
private static final long serialVersionUID = 1L;
...
#OneToMany(fetch = FetchType.LAZY, orphanRemoval = true, mappedBy = "process")
#OrderColumn(name = "process_msg_id")
#LazyCollection(LazyCollectionOption.EXTRA)
private List<MsgEntity> msgList;
#FilterDef(
name = "analystProcessUnanalyzedMsgsFilter",
parameters = { #ParamDef(name = "processIds", type = "integer"), #ParamDef(name = "analystIds", type = "integer") })
#Entity
#Table(name = "msg", schema = "analyst")
public class MsgEntity implements JPAEntity {
...
#ManyToOne(cascade = CascadeType.ALL, optional = false)
#JoinColumn(name = "analystprocess_id", referencedColumnName = "id")
private AnalystProcessEntity process;
#Column(name = "process_msg_id")
private Integer processMsgId;
Additionally, I ran into another problem with null's appearing in the collection, despite the fact that I am using an #OrderColumn, which I thought fixed that issue. It seems that with the use of the #Filter, null's are inserted in place of what ended up being filtered OUT (excluded).

The type of field isn't supported by declared persistence strategy "OneToMany"

We are new to JPA and trying to setup a very simple one to many relationship where a pojo called Message can have a list of integer group id's defined by a join table called GROUP_ASSOC. Here is the DDL:
CREATE TABLE "APP"."MESSAGE" (
"MESSAGE_ID" INTEGER NOT NULL GENERATED ALWAYS AS IDENTITY (START WITH 1, INCREMENT BY 1)
);
ALTER TABLE "APP"."MESSAGE" ADD CONSTRAINT "MESSAGE_PK" PRIMARY KEY ("MESSAGE_ID");
CREATE TABLE "APP"."GROUP_ASSOC" (
"GROUP_ID" INTEGER NOT NULL,
"MESSAGE_ID" INTEGER NOT NULL
);
ALTER TABLE "APP"."GROUP_ASSOC" ADD CONSTRAINT "GROUP_ASSOC_PK" PRIMARY KEY ("MESSAGE_ID", "GROUP_ID");
ALTER TABLE "APP"."GROUP_ASSOC" ADD CONSTRAINT "GROUP_ASSOC_FK" FOREIGN KEY ("MESSAGE_ID")
REFERENCES "APP"."MESSAGE" ("MESSAGE_ID");
Here is the pojo:
#Entity
#Table(name = "MESSAGE")
public class Message {
#Id
#Column(name = "MESSAGE_ID")
#GeneratedValue(strategy = GenerationType.IDENTITY)
private int messageId;
#OneToMany(fetch=FetchType.LAZY, cascade=CascadeType.PERSIST)
private List groupIds;
public int getMessageId() {
return messageId;
}
public void setMessageId(int messageId) {
this.messageId = messageId;
}
public List getGroupIds() {
return groupIds;
}
public void setGroupIds(List groupIds) {
this.groupIds = groupIds;
}
}
I know this is wrong as there is no #Column mapping to GROUP_ASSOC.GROUP_ID for the groupIds property, but hopefully this illustrates what we are trying to do. When we run the following test code we get <openjpa-1.2.3-SNAPSHOT-r422266:907835 fatal user error> org.apache.openjpa.util.MetaDataException: The type of field "pojo.Message.groupIds" isn't supported by declared persistence strategy "OneToMany". Please choose a different strategy.
Message msg = new Message();
List groups = new ArrayList();
groups.add(101);
groups.add(102);
EntityManager em = Persistence.createEntityManagerFactory("TestDBWeb").createEntityManager();
em.getTransaction().begin();
em.persist(msg);
em.getTransaction().commit();
Help!
When you are working with JPA, you should think Object and relations between Objects and you should map your Object model, not ids, to your relational model (it is possible to map a List of basic values with #ElementCollection in JPA 2.0 though but what I said just before still applies).
Here, (assuming this really is a one-to-many relation between Message and GroupAssoc and not a many-to-many relation between Message and Group entities) you should have something like this:
#Entity
#Table(name = "MESSAGE")
public class Message implements Serializable {
#Id
#Column(name = "MESSAGE_ID")
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long messageId;
#OneToMany(fetch=FetchType.LAZY, cascade=CascadeType.PERSIST)
private List<GroupAssoc> groupAssocs = new ArrayList<GroupAssoc>();
public Long getMessageId() {
return messageId;
}
public void setMessageId(Long messageId) {
this.messageId = messageId;
}
public List<GroupAssoc> getGroupAssocs() {
return groupAssocs;
}
public void setGroupAssocs(List<GroupAssoc> groupAssocs) {
this.groupAssocs = groupAssocs;
}
// equals() and hashCode()
}
And another entity for GroupAssoc.
PS: Your DDL really looks like a (M:N) relation between MESSAGE and GROUP (or I don't understand the PK constraint of GROUP_ASSOC) but you didn't show any FK constraint on GROUP_ID so I'm not 100% sure. But if that's the case, then you should use an #ManyToMany instead of #OneToMany.

Persisting a List of Integers with JPA?

We have a pojo that needs to have a list of integers. As an example, I've created a Message pojo and would like to associate a list of groupIds (these ids need to be queried and displayed in the UI). So ideally, we would like to be able to do something like this:
Message msg = em.find(Message.class, 101);
List<Integer> groupIds = msg.getGroupIds();
I was under the impression that this would require only one pojo with JPA, but according to the discussion here, I need to create a second pojo because JPA works in terms of objects instead of primitive types.
From that discussion I've tried the following example code, but I get the error openjpa-1.2.3-SNAPSHOT-r422266:907835 fatal user error: org.apache.openjpa.util.MetaDataException: The type of field "pojo.Group.messageId" isn't supported by declared persistence strategy "ManyToOne". Please choose a different strategy.
DDL:
CREATE TABLE "APP"."MESSAGE" (
"MESSAGE_ID" INTEGER NOT NULL GENERATED ALWAYS AS IDENTITY (START WITH 1, INCREMENT BY 1),
"AUTHOR" CHAR(20) NOT NULL
);
ALTER TABLE "APP"."MESSAGE" ADD CONSTRAINT "MESSAGE_PK" PRIMARY KEY ("MESSAGE_ID");
CREATE TABLE "APP"."GROUP_ASSOC" (
"GROUP_ID" INTEGER NOT NULL,
"MESSAGE_ID" INTEGER NOT NULL
);
ALTER TABLE "APP"."GROUP_ASSOC" ADD CONSTRAINT "GROUP_ASSOC_PK" PRIMARY KEY ("MESSAGE_ID", "GROUP_ID");
ALTER TABLE "APP"."GROUP_ASSOC" ADD CONSTRAINT "GROUP_ASSOC_FK" FOREIGN KEY ("MESSAGE_ID")
REFERENCES "APP"."MESSAGE" ("MESSAGE_ID");
POJOs:
#Entity
#Table(name = "MESSAGE")
public class Message {
#Id
#Column(name = "MESSAGE_ID")
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long messageId;
#OneToMany
private List<Group> groups = new ArrayList<Group>();
#Column(name = "AUTHOR")
private String author;
// getters/setters ommitted
}
#Entity
#IdClass(pojo.Group.GroupKey.class)
#Table(name = "GROUP_ASSOC")
public class Group {
#Id
#Column(name = "GROUP_ID")
private Long groupId;
#Id
#Column(name = "MESSAGE_ID")
#ManyToOne
private Long messageId;
public static class GroupKey {
public Long groupId;
public Long messageId;
public boolean equals(Object obj) {
if(obj == this) return true;
if(!(obj instanceof Group)) return false;
Group g = (Group) obj;
return g.getGroupId() == groupId && g.getMessageId() == messageId;
}
public int hashCode() {
return ((groupId == null) ? 0 : groupId.hashCode())
^ ((messageId == null) ? 0 : messageId.hashCode());
}
}
// getters/setters ommitted
}
Test Code:
EntityManager em = Persistence.createEntityManagerFactory("JPATest").createEntityManager();
em.getTransaction().begin();
Message msg = new Message();
msg.setAuthor("Paul");
em.persist(msg);
List<Group> groups = new ArrayList<Group>();
Group g1 = new Group();
g1.setMessageId(msg.getMessageId());
Group g2 = new Group();
g2.setMessageId(msg.getMessageId());
msg.setGroups(groups);
em.getTransaction().commit();
This all seems ridiculous -- 3 classes (if you include the GroupKey composite identity class) to model a list of integers -- isn't there a more elegant solution?
This is an old topic but things have changed since OpenJPA2, now you can directly persist primitive types or String object. Use ElementCollection annotation to use simple one-to-many linking, no need to intermediate object or link tables. This is how most of us probably create SQL schemas.
#Entity #Table(name="user") #Access(AccessType.FIELD)
public class User {
#Id #GeneratedValue(strategy=GenerationType.IDENTITY)
private long id; // primary key (autogen surrogate)
private String name;
// ElementCollection provides simple OneToMany linking.
// joinColumn.name=foreign key in child table. Column.name=value in child table
#ElementCollection(fetch=FetchType.LAZY)
#CollectionTable(name="user_role", joinColumns={#JoinColumn(name="user_id")})
#Column(name="role")
private List<String> roles;
public long getId() { return id; }
public void setId(long id) { this.id = id; }
public String getName() { return name; }
public void setName(String name) { this.name=name; }
public List<String> getRoles() { return roles; }
public void setRoles(List<String> roles) { this.roles=roles; }
}
- - -
CREATE TABLE user (
id bigint NOT NULL auto_increment,
name varchar(64) NOT NULL default '',
PRIMARY KEY (id),
UNIQUE KEY USERNAME (name)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 ;
CREATE TABLE user_role (
user_id bigint NOT NULL,
role varchar(64) NOT NULL default '',
PRIMARY KEY (user_id, role)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 ;
I really think that what you have is in fact a many-to-many association between two Entities (let's call them Message and Group).
The DDL to represent this would be:
CREATE TABLE "APP"."MESSAGE" (
"MESSAGE_ID" INTEGER NOT NULL GENERATED ALWAYS AS IDENTITY (START WITH 1, INCREMENT BY 1),
"AUTHOR" CHAR(20) NOT NULL
);
ALTER TABLE "APP"."MESSAGE" ADD CONSTRAINT "MESSAGE_PK" PRIMARY KEY ("MESSAGE_ID");
CREATE TABLE "APP"."GROUP" (
"GROUP_ID" INTEGER NOT NULL GENERATED ALWAYS AS IDENTITY (START WITH 1, INCREMENT BY 1)
);
ALTER TABLE "APP"."GROUP" ADD CONSTRAINT "GROUP_PK" PRIMARY KEY ("GROUP_ID");
CREATE TABLE "APP"."MESSAGE_GROUP" (
"GROUP_ID" INTEGER NOT NULL,
"MESSAGE_ID" INTEGER NOT NULL
);
ALTER TABLE "APP"."MESSAGE_GROUP" ADD CONSTRAINT "MESSAGE_GROUP_PK" PRIMARY KEY ("MESSAGE_ID", "GROUP_ID");
ALTER TABLE "APP"."MESSAGE_GROUP" ADD CONSTRAINT "MESSAGE_GROUP_FK1" FOREIGN KEY ("MESSAGE_ID")
REFERENCES "APP"."MESSAGE" ("MESSAGE_ID");
ALTER TABLE "APP"."MESSAGE_GROUP" ADD CONSTRAINT "MESSAGE_GROUP_FK2" FOREIGN KEY ("GROUP_ID")
REFERENCES "APP"."MESSAGE" ("GROUP_ID");
And the annotated classes:
#Entity
public class Message {
#Id
#Column(name = "MESSAGE_ID")
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long messageId;
#ManyToMany
#JoinTable(
name = "MESSAGE_GROUP",
joinColumns = #JoinColumn(name = "MESSAGE_ID"),
inverseJoinColumns = #JoinColumn(name = "GROUP_ID")
)
private List<Group> groups = new ArrayList<Group>();
private String author;
//...
}
#Entity
public class Group {
#Id
#GeneratedValue
#Column(name = "GROUP_ID")
private Long groupId;
#ManyToMany(mappedBy = "groups")
private List<Message> messages = new ArrayList<Message>();
//...
}
I'm not sure you need a bi-directional association though. But you definitely need to start to think object if you want to use JPA (in you're example, you're still setting ids, you should set Entities). Or maybe JPA is not what you need.
isn't there a more elegant solution?
I'm not sure "elegant" is appropriate but JPA 2.0 defines an ElementCollection mapping (as I said in my previous answer):
It is meant to handle several non-standard relationship mappings. An ElementCollection can be used to define a one-to-many relationship to an Embeddable object, or a Basic value (such as a collection of Strings).
But that's in JPA 2.0. In JPA 1.0, you would have to use a provider specific equivalent, if your provider does offer such an extension. It appears that OpenJPA does with #PersistentCollection.
Based on your schema you have a ManyToOne relationship between Group and Message. Which means that a single Message can belong to multiple groups, but each group can have a single message.
The entities would look something like this.
#Entity
#Table(name = "GROUP_ASSOC")
public class Group {
#Id
#Column(name="GROUP_ID")
private int id;
#ManyToOne
#Column(name="MESSAGE_ID")
#ForeignKey
private Message message;
// . . .
}
#Entity
public class Message {
#Id
#GeneratedValue(strategy=GenerationType.IDENTITY)
#Column(name = "MESSAGE_ID")
private int id;
#Column(length=20)
private String author;
#OneToMany(mappedBy="message")
private Collection<Group> groups;
}
There's no need for an IDClass in your app (you only need one if your ID is contains multiple columns).
To get the groupIds for a given message you could write a query like this one
Query q = em.createQuery("Select g.id from Group g where g.message.id = :messageId");
q.setParameter("messageId", 1);
List results = q.getResultList();
Or just iterate over Message.getGroups() :
Message m = em.find(Message.class, 1);
for(Group g : m.getGroups()) {
// create a list, process the group whatever fits.
}