I've a springboot app where I need to implement db partitioning (by "range") for posts table based on posted_at attribute value.
Entity:
#Entity
public class Post {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(updatable = false, nullable = false)
private BigInteger id;
private String title;
private Date postedDate;
.....
}
Liquibase migration:
<databaseChangeLog
xmlns="http://www.liquibase.org/xml/ns/dbchangelog"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.liquibase.org/xml/ns/dbchangelog http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-3.0.xsd">
<changeSet id="00001" author="author">
<sql splitStatements="true">
CREATE TABLE posts (
id bigint primary key,
title varchar(200),
posted_at timestamp with time zone) PARTITION BY RANGE (posted_at)
</sql>
</changeSet>
When I run the above db migration, Postgres complains that I should add primary key also into the partition keys which I don't really want to. If I remove the primary key from the table, JPA will start throwing exception saying that I cannot have an entity without #Id field. How can this be resolved?
PS: I'm using plain sql inside Liquibase migration as liquibase has no direct support for db partitioning.
Related
Table 'liquibase_db.hibernate_sequence' doesn't exist.So I am getting this type of error while I post data from the postman. I tried to solve that problem I tried to add hibernate sequence It's not working.
With the generation GenerationType.AUTO hibernate will look for the default hibernate_sequence table , so change generation to IDENTITY as below :
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
Reference:
200+ accepted as answer to: Table 'DBNAME.hibernate_sequence' doesn't exist
I have a very simple many to many scenario: One ORDER has many PRODUCT, and each product can belong to many orders.
order :
#Entity
#Table(name = "ORDER")
public class OrderEntity {
#Id
#Column(name="ORDER_ID")
#GeneratedValue(strategy = GenerationType.AUTO)
private long id;
#Column(name="ORDER_NAME")
private String name;
#Column(name="ORDER_DATE")
private Date date;
#ManyToMany
private List<ProductEntity> selectedProducts = new ArrayList<>();
product:
#Entity
#Table(name = "PRODUCT")
public class ProductEntity {
#Id
#Column(name="PRODUCT_ID")
#GeneratedValue(strategy = GenerationType.AUTO)
private long id;
#Column(name="PRODUCT_NAME")
private String name;
#Column(name="PRODUCT_PRICE")
private BigDecimal price;
#ManyToMany
private List<OrderEntity> orders = new ArrayList<>();
(removed getters and setters and constructors for brevity)
However when I startup bootstrap then I get a whole host of errors :
Error executing DDL "drop table order if exists" via JDBC Statement
Syntax error in SQL statement "DROP TABLE ORDER[*] IF EXISTS "; expected "identifier"; SQL statement:
Error executing DDL "create table order (order_id bigint not null, order_date timestamp, order_name varchar(255), primary key (order_id))" via JDBC Statement
Syntax error in SQL statement "CREATE TABLE ORDER[*] (ORDER_ID BIGINT NOT NULL, ORDER_DATE TIMESTAMP, ORDER_NAME VARCHAR(255), PRIMARY KEY (ORDER_ID)) "; expected "identifier"; SQL statement:
create table order (order_id bigint not null, order_date timestamp, order_name varchar(255), primary key (order_id)) [42001-199]
Error executing DDL "alter table order_selected_products add constraint FKrbll8c9ubhjqangdfw2sgkurw foreign key (order_entity_order_id) references order" via JDBC Statement
Syntax error in SQL statement "ALTER TABLE ORDER_SELECTED_PRODUCTS ADD CONSTRAINT FKRBLL8C9UBHJQANGDFW2SGKURW FOREIGN KEY (ORDER_ENTITY_ORDER_ID) REFERENCES ORDER[*] "; expected "identifier"; SQL statement:
alter table order_selected_products add constraint FKrbll8c9ubhjqangdfw2sgkurw foreign key (order_entity_order_id) references order [42001-199]
Error executing DDL "alter table product_orders add constraint FK9pa3r9u6x44jjxrkkhdvhu23k foreign key (orders_order_id) references order" via JDBC Statement
Syntax error in SQL statement "ALTER TABLE PRODUCT_ORDERS ADD CONSTRAINT FK9PA3R9U6X44JJXRKKHDVHU23K FOREIGN KEY (ORDERS_ORDER_ID) REFERENCES ORDER[*] "; expected "identifier"; SQL statement:
alter table product_orders add constraint FK9pa3r9u6x44jjxrkkhdvhu23k foreign key (orders_order_id) references order [42001-199]
I'm not sure why there are these syntax errors. Is this some kind of SQL dialect issue?
ORDER is a very common reserved keyword and that is the root cause of the errors you see.
Change your table name to something else, such as ORDERS, or if you really want to use that name you can try escaping it:
#Entity
#Table(name = "\"ORDERS\"")
public class OrderEntity {
....
}
List of reserved keywords for some common databases:
https://docs.oracle.com/cd/B28359_01/appdev.111/b31231/appb.htm#BABDFFBA
https://learn.microsoft.com/en-us/sql/t-sql/language-elements/reserved-keywords-transact-sql?view=sql-server-2017
https://www.postgresql.org/docs/current/sql-keywords-appendix.html
https://dev.mysql.com/doc/refman/8.0/en/keywords.html
My spring boot project uses an existing database, I have a new model entity/table in my project that must have a foreign key constraint with an existing table in the database.
I've tried to find solution online but all the answers are for the case where both the tables are present as entities in that project and using some #ManyToOne, #OneToMany annotations.
I can't define those annotations because I don't have the reference table as an entity or model in my project.
Let's say I have class like:
#Entity(name = "user")
public class User {
#Id
#GeneratedValue
private long userId;
private long departmentId;
I want to put a foreign key contraint on the departmentId column to reference to id column of the existing department table that isn't defined as a model or entity in my project.
Thanks
Just do it as normal
example
#Column(name = "department_id")
private Department departmentId;
You can later access it Department.departmentId. Hope this helps.
Try it like this
#ManyToOne
#JoinColumn(name="(column name of current entity)", referencedColumnName="(column name in target entity)")
private Department departmentId;
you can skip the referencedColumnName if the column name is same in both the entities
I have two entities :
#Entity
#Table(name="Registration")
public class Registration{
#Id
private UUID uuid;
#OneToMany(cascade = {CascadeType.PERSIST, CascadeType.REMOVE, CascadeType.MERGE}, fetch = FetchType.LAZY)
#JoinColumn(name="registration", nullable = false)
private List<Payment> payment;
}
#Entity
#Table(name="Payment")
public class Payment {
#Id
private UUID uuid;
/*#ManyToOne(targetEntity = Registration.class) <-- MappingException: Repeated column in mapping for entity
private Registration registration;*/
}
This entities create two tables :
TABLE `registration` (
`uuid` binary(16) NOT NULL,
PRIMARY KEY (`uuid`))
TABLE `payment` (
`uuid` binary(16) NOT NULL,
`registration` binary(16) NOT NULL,
PRIMARY KEY (`uuid`),
CONSTRAINT `FK_jgemihcy9uethvoe3l7mx2bih` FOREIGN KEY (`registration`) REFERENCES `registration` (`uuid`))
I'm using Rest Service. I can access to
registration.payment
but not
payment.registration
why ? I need a relation oneToMany bidirectionnal ?
Yes, you need to add the payment.registration #ManyToOne relationship if you use it in your code.
Take into account that JPA allows you to map a SQL database model to an object oriented one. Once you have the mapping between your objects and your database, you always work at the object level. That's why, although you have the relationship in the database, your Payment object doesn't know anything about it unless you map it to an attribute.
Of course it applies when you are using you data model objects or performing JPQL or Criteria queries. If you use native queries you have access to the database model as it is.
In my spring mvc app, i have the following object. I am trying to make a visual of data using devtool in my app.
#Entity
#Data
public class ConsultationRequest {
#Id
#GeneratedValue
private Long id;
private String name;
private String email;
private String purpose;
private String programme;
private int year;
private String language;
private String comments;
#Enumerated(EnumType.STRING)
private ConsultationStatus status;
}
Then i used the jpa to make the entity:
#Repository
public interface ConsultationRequestRepository extends JpaRepository<ConsultationRequest, Long> {
}
The problem is when i load my application, i face with 2 errors:
Unsuccessful: drop sequence hibernate_sequence
[36morg.hibernate.tool.hbm2ddl.SchemaExport Sequence "HIBERNATE_SEQUENCE" not found; SQL statement:
Then when i open the
http://localhost:8080/h2-console/
I cannot see the table.
It seems that the in the boot process, table is not made.
Update your code as below:
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
As you have not specified a sequence table name, hibernate will look for a sequence table named as hibernate_sequence and use it as default.
For Oracle/Postgres, increment fields used are sequence tables.
In MySql, there are increment fields that automatically increment.
If someone is getting this error with Spring Boot testing(with H2) , we have to use following in the application.properties(or whatever profile we are using) :
spring.jpa.hibernate.ddl-auto=create-drop
Setting the following property in the properties file helped me solve the hibernate_sequence problem for hibernate 5.4v
spring:
jpa:
hibernate:
use-new-id-generator-mappings: false
Check persistence.xml
property name="hibernate.hbm2ddl.auto" value="create"
not hdm2ddl
This worked in my case.
SQL operation ERROR when start app spring-boot.
I added the setting in spring properties and solved: in the spring:jpa.hibernate.ddl-auto= create-drop to hibernate be able create or drop table automatically.
If you use a 2nd cache with liquidbase, you have to add the sequence in the changelog like this:
<changeSet author="liquibase-docs"
id="createSequence-example">
<createSequence catalogName="cat" cycle="false"
incrementBy="1" ordered="true" schemaName="public"
sequenceName="hibernate_sequence" startValue="0" />
</changeSet>
For spring-boot 2.7.x and h2 2.x you need to add MODE=LEGACY; in the database connection:
example application.yml:
spring:
datasource:
url: jdbc:h2:mem:test;MODE=LEGACY;
exemple application.properties:
spring.datasource.url=jdbc:h2:mem:test;MODE=LEGACY;
For Mysql:
the auto-increment is not added, modify ur table:
ALTER TABLE table_name MODIFY COLUMN id BIGINT AUTO_INCREMENT=1