We Keep Coding

ManyToOne on column that is not unique

I have one table Message in which I keep both incoming and outgoing messages. A column "category" is kept to differentiate, that can have 1 = INCOMING, 2 = OUTGOING. Outgoing messages can have attachments. The following is my Message entity class:
#Entity("MESSAGE")
class Message{
Long id; //primary key
String additionalStringId;
private Long senderId;
private Long receiverId;
Category messageCategory;
#OneToMany(
mappedBy = "message",
cascade = CascadeType.ALL,
orphanRemoval = true)
private List<AttachmentEntity> outgoingAttachments= new ArrayList<>();
}
The problem is that AttachmentEntity is linked with the message via the "additionalStringId" and I can not impact the database schema.
class AttachmentEntity{
#ManyToOne
#JoinColumn(name = "additionalStringId", referencedColumnName = "additionalStringId")
private Message message;
}
I know it's not working snipping code but my problem appears when sender = receiver, when I try to send a message to myself. In that case in my database I will have two messages, with the same additionalStringId but with category = 1 and the other with category = 2. My attachment entity list tries to link to message but two messages are visible. What can I do to fix this problem?
I tried separating the two categories into separate entities with #Where and #DiscriminatorFormula and #DiscriminatorValue but I could not get it to work. What can I do?
Table DDLs:
CREATE TABLE "MESSAGE"
( "ID" NUMBER NOT NULL ENABLE,
"MESSAGE_ID" VARCHAR2(60) NOT NULL ENABLE,
"CATEGORY" NUMBER,
"SENDER_ID" NUMBER,
"RECEIVER_ID" NUMBER )
CREATE TABLE "OUTBOX_ATTACHMENT"
( "ID" NUMBER NOT NULL ENABLE,
"MESSAGE_ID" VARCHAR2(60) NOT NULL ENABLE,
)

#ManyToOne(cascade = CascadeType.PERSIST)
#JoinColumn(name = "additionalStringId", referencedColumnName = "id", nullable = false)
private Message message;
#OneToMany(mappedBy = "message", cascade = CascadeType.ALL, fetch = FetchType.LAZY)
private List<AttachmentEntity> outgoingAttachments = new ArrayList<>();
something like this might work.

I think the problem you are facing is not at the JPA level, but at the table definition level (DDL).
If you change the table definition as shown below, the FK relationship becomes easy to establish:
CREATE TABLE "MESSAGE"
( "ID" NUMBER NOT NULL,
"MESSAGE_ID" VARCHAR2(60) NOT NULL,
"CATEGORY" NUMBER,
"SENDER_ID" NUMBER,
"RECEIVER_ID" NUMBER,
constraint uq1 unique (category, message_id)
);
CREATE TABLE "OUTBOX_ATTACHMENT"
( "ID" NUMBER NOT NULL ,
category number not null constraint chk1 check (category = 2),
"MESSAGE_ID" VARCHAR2(60) NOT NULL ,
constraint fk1 foreign key (category, message_id)
references message (category, message_id)
);
As you can see the FK includes two columns: category, and message_id. But, as per requirements, in the attachement table category can only accept attachment to outgoing messages (value 2).

Problem with ManyToMany relations in spring data. It changed my table

I had a db with tables SPEC and PARTS.Also I had a table for MANY TO MANY relations. In my project I used spring jdbs template and all works good. Then I decide to change jdbc on SPring data jpa.
My Entities:
#Entity
#Table(name = "PARTS")
public class PartsJpa {
#Id
private int id;
#Column(name = "NAME")
private String name;
#OneToOne(cascade = CascadeType.ALL, fetch = FetchType.EAGER)
#JoinColumn(name = "ID_EXPORT", unique = false, nullable = false, updatable = true)
private ExportJpa exportJpa;
#OneToOne(cascade = CascadeType.ALL, fetch = FetchType.EAGER)
#JoinColumn(name = "ID_TYPE", unique = false, nullable = false, updatable = true)
private TypesJpa typesJpa;
#Column(name = "DESCRIPTION")
private String description;
#ManyToMany(fetch = FetchType.EAGER)
#JoinTable(name="SPEC_PARTS",
joinColumns = #JoinColumn(name="ID_SPEC", referencedColumnName="id"),
inverseJoinColumns = #JoinColumn(name="ID_PARTS", referencedColumnName="id")
)
private Set<SpecJpa> specJpa;
////////
}
And Spec:
#Entity
#Table(name = "SPEC")
public class SpecJpa {
#Id
private int id;
#Column(name = "NAME")
private String name;
#OneToOne(cascade = CascadeType.ALL, fetch = FetchType.EAGER)
#JoinColumn(name = "Creator_ID", unique = false, nullable = false, updatable = true)
private UsersJpa usersJpa;
#Column(name = "DESCRIPTION")
private String description;
#ManyToMany(fetch = FetchType.EAGER)
#JoinTable(name="SPEC_PARTS",
joinColumns = #JoinColumn(name="ID_SPEC", referencedColumnName="id"),
inverseJoinColumns = #JoinColumn(name="ID_PARTS", referencedColumnName="id")
)
private Set<PartsJpa> partsJpa;
////////////////
}
I don't show getters and setters.
It works, but when I start a programm, something in my table was changed and now I can't add in table spec_parts values like(1,3)(1,2).
Mistake:
FK_123: PUBLIC.SPEC_PARTS FOREIGN KEY(ID_PARTS) REFERENCES PUBLIC.SPEC(ID) (3)" Referential integrity constraint violation: "FK_123: PUBLIC.SPEC_PARTS FOREIGN KEY(ID_PARTS) REFERENCES PUBLIC.SPEC(ID) (3)"; SQL statement: INSERT INTO "PUBLIC"."SPEC_PARTS"("ID_SPEC","ID_PARTS")VALUES(?,?)
Maybe I have mistake with creating relations between spec and parts? What problem it can be?
data in spec
ID NAME CREATOR_ID DESCRIPTION CHANGER_ID
1 pc 1 description 1
2 pc2 2 description2 2
data in parts
ID ▼ NAME ID_EXPORT ID_TYPE DESCRIPTION
1 intel core i5 1 1 d1
2 intel core i7 1 1 d2
3 ddr3 2 2 d3
4 ddr4 2 2 d4
5 asus 3 3 d5
data in spec_parts now:
ID_SPEC ID_PARTS
1 1
2 2
so I can't add 1,3 or 2,4
I find a problem, spring date change something and now in table SPEC_PARTS ID_SPEC mapping on PARTS.ID. Why?

As you are using ManyToMany relation, there is a mapping table created named SPEC_PARTS which have referenced columns ID_SPEC and ID_PARTS.These columns value come from SPEC.ID and PARTS.ID. So you can't insert in SPEC_PARTS without creating referenced value because you are trying to do foreign key constraint violation.
Suppose if there is a row in SPEC with id value 1 and there is a row in PARTS with id value 2. Then you can insert in SPEC_PARTS with value like (1,2).
So, first, add data in SPEC and PARTS then map them in SPEC_PARTS.
And you can remove #JoinTable from one side, you don't need to define it both side.
Update:
Problem is SpecJpa class relation. Here you are using SPEC_PARTS.ID_SPEC as foriegn key for PARTS.ID and SPEC_PARTS.ID_PARTS as foriegn key for SPEC.ID which is fully reversed what you do in PartsJpa class.
#JoinTable(name="SPEC_PARTS",
joinColumns = #JoinColumn(name="ID_SPEC", referencedColumnName="id"),
inverseJoinColumns = #JoinColumn(name="ID_PARTS", referencedColumnName="id")
)
That's why this error say
SPEC_PARTS FOREIGN KEY(ID_PARTS) REFERENCES PUBLIC.SPEC(ID) (3)";
There is no SPEC.ID value 3 exist in the database.
Solution:
Remove #JoinTable from SpecJpa class as you don't need to specify both side.
And remove the wrong relation of the foreign key from database also.

#JoinColumn gives error "column with logical name ID not found" in Hibernate 4

I am having below annotation on column in my entity class.
#OneToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "INQUIRYID", referencedColumnName="ID", updatable=false, insertable=false)
private MyTable myInquiry;
It was giving below error on runtime.
column with logical name ID not found in entity class
As the referenced column is a primary key, I removed the referencedColumnName attribute and updated to below
#OneToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "INQUIRYID", updatable=false, insertable=false)
private MyTable myInquiry;
This works perfectly with Hibernate 5.3 but as soon as I go to hibernate 4 , I see some anomalies.
In hibernate 5 I get this issue only with columns which are referring some ID(PK) of another class. However, in hibernate 4 I see this error for non-pk columns as well.
I start to get the same error for columns which are referring non primary keys.
#ManyToOne(fetch = FetchType.EAGER)
#JoinColumn(name = "AB", referencedColumnName = "AB")
private MyTable someData;
Above code gives me error in hibernate 4
Column with logical name AB not found in entity class.
Here, AB is a non primary key column .So I can't remove referencedColumnName attribute.
Is it purely because of hibernate version or there is a different reason for such behavior ?
Referred this : Similar Issue

There is a bug for hibernate 4.1.7
A workaround for this issue is surrounding the column name with gave accents.
Unable to find column with logical name: id in
org.hibernate.mapping.Table(template) and its related supertables and
secondary tables
#ManyToOne #JoinColumnsOrFormulas({ #JoinColumnOrFormula(column =
#JoinColumn(name = "template", referencedColumnName = "id")),
#JoinColumnOrFormula(formula = #JoinFormula(value = "'custom'",
referencedColumnName = "type")) }) This is caused by identifying the
column names within the logicalToPhysical map of
TableColumnNameBinding. Within this map the column names are
surrounded by grave accents (`id`) while the check do a lookup to the
map with plain column name (id).
A workaround for this issue is surrounding the column name with gave
accents.
#ManyToOne #JoinColumnsOrFormulas({ #JoinColumnOrFormula(column =
#JoinColumn(name = "template", referencedColumnName = "`id`")),
#JoinColumnOrFormula(formula = #JoinFormula(value = "'custom'",
referencedColumnName = "`type`")) })

Hibernate join using non-primary key column

I have two tables:
users:
user_id (primary)
ip (unique)
etc ..
services_to_ip
id (primary)
service_id
ip
etc ..
In class User:
#OneToMany()
#JoinColumn(name = "ip", insertable = false, nullable = false, updatable = false)
public List<QPlanService> getPlanServices() {
return planServices;
}
Using MySQL query log we get something like that:
SELECT *
FROM services_users planservic0_
LEFT OUTER JOIN services qservice1_
ON planservic0_.service_id = qservice1_.id
WHERE planservic0_.ip = 777
In WHERE condition the 'user_id' field used (the default field is primary key - users.id) (user_id=777).
How can I specify that I need to take the value of the 'ip' field from User entity, not 'user_id'?
I will be grateful for any help!

JoinColumn will only specify the name of the column holding the foreign key, so changing the name of joincolumn absolutely will not help.
Hibernate will be using the primary key by default for joining, if you want to override this you can simply use referencedColumnName in your relation, but the referenced column should be unique

As Amer Qarabsa mentioned above:
#OneToMany()
#JoinColumn(name = "ip", insertable = false, nullable = false, updatable = false, referencedColumnName="ipcolumnName")
public List<QPlanService> getPlanServices() {
return planServices;
}

#ManyToOne, Can one column reference to two other Columns?

Can I have a relationship as below:
#Entity Table1{
#ManyToOne
#JoinColumn(name = "Column1",
referencedColumnName = "t2id",
insertable = false,
updatable = false)
private Table2 table2_col;
#ManyToOne
#JoinColumn(name = "Column1",
referencedColumnName = "t3id",
insertable = false,
updatable = false)
private Table3 table3_col;
}

Yes, the mapping looks valid.
The column Column1 in both cases belong to different tables (Table2.column1 and Table3.column1). So I don't see any collision here. It is not the case as the tittle says "one column references to two other columns".
In this case you have two many-to-one relations: Table1<--->Table2 and Table1<--->Table3. So the column1 in both tables (2 and 3) is a Foreign Key to the Table1. So you have 2 different foreign keys.