I have 2 related tables and i am wondering if it is possible to include other columns (like firstname and surname) from table no1 when i am calling the function ListAll() in table no2? I am using JPA with Session Beans (AbstractFacade) and JSF Pages. Thanks in advance :-)
Table No1
CREATE TABLE cases (
caseid INT AUTO_INCREMENT PRIMARY KEY,
category VARCHAR(32),
descript VARCHAR(512),
isDone TINYINT,
userid INT,
INDEX user_ind(userid),
FOREIGN KEY (userid) REFERENCES USERS(userid)
);
Table 2
CREATE TABLE users (
userid INT NOT NULL AUTO_INCREMENT,
firstname VARCHAR(64) NOT NULL,
surname VARCHAR(64) NOT NULL,
telephone VARCHAR(12),
email VARCHAR(64),
PRIMARY KEY (userid)
);
Entity Controller
#Named(value = "caseController")
#SessionScoped
public class CaseController implements Serializable {
#EJB
CasesFacade casesFacade;
#Inject
CasesBean casesBean;
public List<Cases> getAll() {
return casesFacade.findAll();
}
If i correct understand maybe the good idea will be unpack chosen columns/fields to custom DTO on level repository or in code.
Related
I have two tables, User and Relationship. The tables are used to store a parent child relationship. I am using Postgres
// schema.sql
CREATE TABLE "public"."Relationships" (
id SERIAL PRIMARY KEY NOT NULL,
parent_id INT NOT NULL,
FOREIGN KEY (parent_id) REFERENCES "User" (id),
child_id INT NOT NULL,
FOREIGN KEY (child_id) REFERENCES "User" (id)
)
CREATE TABLE "public"."User" (
id SERIAL PRIMARY KEY NOT NULL,
name VARCHAR(128) NOT NULL,
email VARCHAR(128) UNIQUE,
password VARCHAR(128) NOT NULL,
isChild BOOLEAN NOT NULL DEFAULT false
created_at TIMESTAMP NOT NULL DEFAULT NOW();
);
When I run npx prisma introspect the following is returned in the schema.prisma file.
// schema.prisma
generator client {
provider = "prisma-client-js"
}
datasource db {
provider = "postgresql"
url = env("DATABASE_URL")
}
model Relationships {
child_id Int
id Int #default(autoincrement()) #id
parent_id Int
User_Relationships_child_idToUser User #relation("Relationships_child_idToUser", fields: [child_id], references: [id])
User_Relationships_parent_idToUser User #relation("Relationships_parent_idToUser", fields: [parent_id], references: [id])
}
model User {
created_at DateTime #default(now())
email String? #unique
id Int #default(autoincrement()) #id
ischild Boolean #default(false)
name String?
password String
Relationships_Relationships_child_idToUser Relationships[] #relation("Relationships_child_idToUser")
Relationships_Relationships_parent_idToUser Relationships[] #relation("Relationships_parent_idToUser")
}
I dont understand what User_Relationships_child_idToUser and User_Relationships_parent_idToUser are and why they are not just the simple syntax that appears for foreign keys in the Prisma docs tutorial.
Prisma's introspection generates two fields for each foreign key:
the relation scalar field (basically the direct representation of the foreign key)
a relation field (annotated with the #relation attribute) – these are the fields that seem to confuse you. The reason they provide is such that you can work with the relations easily in the Prisma Client API.
You can find more info about this in the docs here.
Of course User_Relationships_parent_idToUser and User_Relationships_child_idToUser are not very nice names. You can manually adjust the schema after introspection and rename the relation fields to have friendlier names, e.g:
model Relationships {
child_id Int
id Int #default(autoincrement()) #id
parent_id Int
child User #relation("Relationships_child_idToUser", fields: [child_id], references: [id])
parent User #relation("Relationships_parent_idToUser", fields: [parent_id], references: [id])
}
When I do anything with a table, it always show the error:
Hibernate: select nextval ('hibernate_sequence')
2019-07-20 16:15:44.877 WARN 58376 --- [nio-9000-exec-1] o.h.engine.jdbc.spi.SqlExceptionHelper : SQL Error: 0, SQLState: 42P01
2019-07-20 16:15:44.877 ERROR 58376 --- [nio-9000-exec-1] o.h.engine.jdbc.spi.SqlExceptionHelper : ERROR: relation "hibernate_sequence" does not exist
I DON'T want to use hibernate_sequence to share id sequence between tables, but want to define id seq for each table and use them respectively.
I use Spring Boot 2.1.6.RELEASE, Spring Data JPA (Hibernate 5.3.10.Final), and Postgres 11.2, and define the id field with BigSerial type and hope to use the id sequence of each table in respective entity class.
The demo repo is here: https://github.com/Redogame/share_hibernate_sequence
Create user table (use identity as table name because user is a Postgres reserved keyword).
By defining id with bigserial type, Postgres will create a identity_id_seq automatically, and I verified that identity_id_seq has been created successfully.
create table identity
(
id bigserial not null
constraint identity_pkey
primary key,
name varchar(255) not null
constraint identity_name_key
unique
constraint identity_name_check
check ((name)::text <> ''::text),
created_date timestamp not null,
created_by_id bigint not null
constraint identity_identity_id_fk
references identity,
last_modified_date timestamp not null,
last_modified_by_id bigint not null
constraint identity_identity_id_fk_2
references identity,
version bigint not null
);
Specify a sequence generator to use this id sequence:
#Table(name = "identity")
public class UserEntity extends Auditable<Long> {
#Id
#SequenceGenerator(name="identity_id_seq", sequenceName = "identity_id_seq", initialValue=1, allocationSize=1)
#GeneratedValue(strategy=GenerationType.SEQUENCE, generator="identity_id_seq")
private Long id;
But it doesn't work. I also tried to config spring.jpa.hibernate.use-new-id-generator-mappings and spring.jpa.properties.hibernate.id.new_generator_mappings, but still not work.
spring:
jpa:
hibernate:
use-new-id-generator-mappings: false
properties:
hibernate:
id:
new_generator_mappings: false
I expect not to use hibernate_sequence, that is: don't execute select nextval ('hibernate_sequence') before/after any SQL statement.
Try the below steps
CREATE SEQUENCE IF NOT EXISTS manual_seq;
Change create table script
create table identity
(
id integer NOT NULL DEFAULT nextval('manual_seq'::regclass),
name varchar(255) not null
constraint identity_name_key
unique
constraint identity_name_check
check ((name)::text <> ''::text),
created_date timestamp not null,
created_by_id bigint not null,
last_modified_date timestamp not null,
last_modified_by_id bigint not null,
version bigint not null,
CONSTRAINT manual_seq_pkey PRIMARY KEY (id)
);
I removed the foreign key constraint for testing purposes.
Update the entity mapping
#Entity
#Table(name = "identity")
#JsonIgnoreProperties(ignoreUnknown = true)
public class UserEntity extends Auditable<Long> {
#Id
#SequenceGenerator(name="manual-seq", sequenceName = "manual_seq",allocationSize = 1)
#GeneratedValue(generator="manual-seq")
private Long id;
#Basic
#Column(name = "name", nullable = false)
private String name;
#MappedSuperclass
#JsonIgnoreProperties({"new", "createdDate", "createdById", "lastModifiedDate", "lastModifiedById", "version"})
abstract class Auditable<PK extends Serializable>{
#NotAudited
#CreatedDate
#Temporal(TemporalType.TIMESTAMP)
private Date createdDate;
#NotAudited
#CreatedBy
private Long createdById;
#LastModifiedDate
#Temporal(TemporalType.TIMESTAMP)
private Date lastModifiedDate;
#LastModifiedBy
private Long lastModifiedById;
#NotAudited
#Version
private Long version;
Revert the spring.jpa.hibernate.use-new-id-generator-mappings
The issue was extending AbstractPersistable because of which database sequence was not getting used. Also, note I have removed the audit for testing purposes.
The same problem was happening to me. I explicitly set spring.jpa.properties.hibernate.id.new_generator_mappings=false but select nextval ('hibernate_sequence') was still run by Hibernate.
I found that when we use the #GeneratedValue annotation without setting a strategy, it defaults to AUTO, which means, Hibernate will try to generate the ID value using hibernate_sequence and then it wil fail because it doesn't exist in the database.
So, I made #GeneratedValue (strategy = GenerationType.IDENTITY) and tried again. In this case, the ID value was generated by my identity column in the database (the primary key that is automatically incremented) and not by hibernate_sequence.
create table users (id serial not null, name varchar(250), primary key (id));
I have 2 DB tables named respectivelly T_ACCOUNT and T_ACCOUNT_BENEFICIARY.
These tables have the following structure:
create table T_ACCOUNT (ID integer identity primary key, NUMBER varchar(9), NAME varchar(50) not null, CREDIT_CARD varchar(16), unique(NUMBER));
create table T_ACCOUNT_BENEFICIARY (ID integer identity primary key, ACCOUNT_ID integer, NAME varchar(50), ALLOCATION_PERCENTAGE decimal(5,2) not null, SAVINGS decimal(8,2) not null, unique(ACCOUNT_ID, NAME));
And the T_ACCOUNT table is bound to the T_ACCOUNT_BENEFICIARY table with a one to many relationship, this is the graphical representation:
So this is the first class named Account that map the T_ACCOUNT table:
#Entity
#Table(name="T_ACCOUNT")
public class Account {
#Id
#GeneratedValue
#Column(name="id")
private Long entityId;
#Column(name="NUMBER")
private String number;
#Column(name="NAME")
private String name;
#OneToMany
#JoinColumn(name="ACCOUNT_ID")
private Set<Beneficiary> beneficiaries = new HashSet<Beneficiary>();
#Column(name="CREDIT_CARD")
private String creditCardNumber;
// GETTERS & SETTERS
}
And this is the Beneficiary class that map the T_ACCOUNT_BENEFICIARY table:
/**
* A single beneficiary allocated to an account. Each beneficiary has a name (e.g. Annabelle) and a savings balance
* tracking how much money has been saved for he or she to date (e.g. $1000).
*/
#Entity
#Table(name="T_ACCOUNT_BENEFICIARY")
public class Beneficiary {
#Id
#GeneratedValue
#Column(name="ID")
private Long entityId;
#Column(name="NAME")
private String name;
#Embedded
#AttributeOverride(name="value",column=#Column(name="ALLOCATION_PERCENTAGE"))
private Percentage allocationPercentage;
#Embedded
#AttributeOverride(name="value",column=#Column(name="SAVINGS"))
private MonetaryAmount savings = MonetaryAmount.zero();
As you can see into the Account I have the beneficiaries field that implement the one to may relationship
#OneToMany
#JoinColumn(name="ACCOUNT_ID")
private Set<Beneficiary> beneficiaries = new HashSet<Beneficiary>();
I know that, on the DB, this relationship is implemented by the ACCOUNT_ID field of the T_ACCOUNT_BENEFICIARY table (so multiple row of the T_ACCOUNT_BENEFICIARY table can have the same value of the ACCOUNT_ID field and this means that a single row of the T_ACCOUNT table can be associated to more than one rows of T_ACCOUNT_BENEFICIARY table).
As you can see in the previous sippet there is the #JoinColumn(name="ACCOUNT_ID") annotation.
My doubt is generated by the fact that I have an ACCOUNT_ID column on my T_ACCOUNT_BENEFICIARY table, infact:
create table T_ACCOUNT_BENEFICIARY (ID integer identity primary key, ACCOUNT_ID integer, NAME varchar(50), ALLOCATION_PERCENTAGE decimal(5,2) not null, SAVINGS decimal(8,2) not null, unique(ACCOUNT_ID, NAME));
but this column seems to not be mapped on the Beneficiary that map this T_ACCOUNT_BENEFICIARY table.
So my doubts is: the #JoinColumn(name="ACCOUNT_ID") is working at relational level performing the join operation on the ACCOUNT_ID column of the table mapped by the Beneficiary entity (T_ACCOUNT_BENEFICIARY) or am I missing something? How exactly is performed this join?
If my interpretation is right can I work at entity level and say to join the beneficiaries field of my Account entity class to a new accountId field inserted into my Beneficiary entity class and mapping the ACCOUNT_ID column of the T_ACCOUNT_BENEFICIARY table?
Tnx
It seems is a Unidirectional OneToMany relationship
In JPA 2.0 a #JoinColumn can be used on a OneToMany to define the foreign key
I'm not sure if I understand your question. But what you have done with your #JoinColumn annotation is correct and Hibernate will execute appropriate SQL statements when you have multiple beneficiaries for your account. For example executing multiple INSERTS if you have two Beneficiaries for an Account. And yes using the #JoinColumn annotation is at the hibernate level. If you want to access an Account from a Beneficiary entity you would need to define a Bidirectional relationship in the Beneficiary class like below.
#Entity
#Table("T_ACCOUNT_BENEFICIARY")
public class Beneficiary {
#ManyToOne(mappedBy = "beneficiaries")
Account account;
...
}
I am having trouble generating my tables in PostgreSQL from Grails. I have simple Email and EmailAttachment domain classes with a hasMany and belongsTo relationship. This setup worked well on our production server (AS400 DB2), but when I try to run my program on PostgreSQL (the new dev environment), the Email class does not have the attachment_id column.
Email.groovy:
class Email {
static hasMany = [attachments:EmailAttachment]
Integer id
Integer version = 0
String subject
String recipients
String sender
Date sentDate
String plainTextMessage
Set attachments
static mapping = {
datasources(['DEFAULT'])
table name:'error_email', schema: Appointment.schema
sort sentDate:'desc'
}
static constraints = {
subject nullable:true
version nullable:true
recipients nullable:true
sender nullable:true
sentDate nullable:true
plainTextMessage nullable:true
attachments nullable:true
}
def String toString(){
return subject
}
}
EmailAttachment.groovy:
class EmailAttachment {
static belongsTo = [email:ErrorEmail]
ErrorEmail email
String filename
byte[] content
static mapping = {
datasources(['DEFAULT'])
table name:'error_email_attachment', schema: Appointment.schema
}
static constraints = {
filename nullable:true
content nullable:true
}
}
Also, here are the relevant lines from schema-export:
alter table program.email_attachment drop constraint FK2E592AFD1D80E229;
drop table program.email cascade;
drop table program.email_attachment cascade;
drop sequence hibernate_sequence;
create table program.email (id int4 not null, version int4, plain_text_message varchar(255), recipients varchar(255), sender varchar(255), sent_date timestamp, subject varchar(255), primary key (id));
create table program.email_attachment (id int8 not null, version int8 not null, content bytea, email_id int4 not null, filename varchar(255), primary key (id));
alter table program.email_attachment add constraint FK2E592AFD1D80E229 foreign key (email_id) references program.error_email;
create sequence hibernate_sequence;
I've tried specifying joinTable: attachments joinTable:[name: 'email_table', column: 'attachment_id', key: 'id'] to no avail, as well as leaving it out, and trying other collection types for attachment. Thanks in advance for your time and brain cells.
The email doesn't have an attachment_id column because it's the one side of the one-to-many. The many side, attachment in this case, has a reference to its owning email in the email_id int4 not null column. Given an email with id 42 you (and Grails/GORM/Hibernate) can find all of the attachments by querying for all rows in that table with email_id=42.
Is it possible to map a one to one relationship using the parent key and a discriminator value? I know that code first does not like the discriminator property on the concrete class and to reference it only in the Map method.
FlightTypes { Inbound = 1, Outbound = 2}
public class Transaction
- int TransactionId
- int? InboundFlightId
- InboundTransactionFlight InboundFlight
- int? OutboundFlightId
- OutboundTransactionFlight OutboundFlight
public abstract class TransactionFlight
- TransactionFlightId
public class InboundTransactionFlight : Flight
- List<Transaction> InboundFor
public class OutboundTransactionFlight : Flight
- List<Transaction> OutboundFor
Entity<InboundTransactionFlight>().Map(m => m.Requires("FlightTypeId").HasValue(1));
Entity<OutboundTransactionFlight>().Map(m => m.Requires("FlightTypeId").HasValue(2));
/* this is what is currently generated */
CREATE TABLE Transactions (
TransactionId int NOT NULL,
InboundFlightId int NULL,
OutboundFlightId int NULL
)
CREATE TABLE TransactionFlights (
TransactionFlightId int NOT NULL,
FlightTypeId int NOT NULL,
...
CONSTRAINT PK_TransactionFlights PRIMARY KEY CLUSTERED ( TransactionFlightId )
)
/* is it possible to generate/map this and keep inheritance? */
CREATE TABLE Transactions (
TransactionId int NOT NULL,
)
CREATE TABLE TransactionFlights (
TransactionId int NOT NULL,
FlightTypeId int NOT NULL,
...
CONSTRAINT PK_TransactionFlights PRIMARY KEY CLUSTERED ( TransactionId, FlightTypeId )
)
Thanks.
As I know it is not possible because EF doesn't allow using discriminator column in any other mapping. Also your target mapping will demand that your transaction class also has FlightTypeId property (class must have properties for the whole key) but it would break the meaning of the inheritance because you would be able to change the value of that property and make your inheritance inconsistent.