Hi I am new to jpql and using spring data jpa with postgres and I am not able to translate below query.
select
"user".table_1.id, "user".table_2.name,
"user".table_2.email
from
"user".table_1
left outer join
"user".table_2
on
"user".table_1.table2_id = "user".table_2.id
where
"user".table_1.parent_id=5
and below is my model classes
#entity
#table(name="table_1)
class Table1{
#id
#GeneratedValue
private Long id;
#OneToOne(mappedBy = "table_2")
private Table2 table_2;
#ManyToOne
#JoinColumn(name = "parent_id")
private Table1 parent_id;
#OneToMany(mappedBy = "account", fetch = FetchType.LAZY)
private List<Table1> childs;
}
#entity
#table(name="table_2)
class Table2
{
#id
private Long id;
private String emailId;
private String name;
#OneToOne
#JoinColumn(name = "table1_id")
private Table1 table1;
}
Since I am using DTO with spring data and I need help I am not able to solve this.
This is best I tried:
#query("select t1.id, t2.name,t2.email from Table1 t1 left outer join
t2.table_2 where t1.parent_id=?1")
public List<CustomDTO>findByParentId(Long parentId);
public class CustomDTO{
private Long table1Id;
private String name;
private String email;
}
I am not able to solve this error as I am getting the hibernate qwery as
select
table10_.id as col_0_0_,
table21_.name as col_1_0_,
table21_.email as col_2_0_
from
"user".table1 table0_
left outer join
"user".table2 table_21_
on table10_.id=table_21_.table_1 where
table0_.parent_id=?
Please help me to solve this error
If you need any help let me know.
Thanks :)
Your JPA query would look like (not tested though)
#Query("select t1.id as table1Id, t2.name as name ,t2.emailId as email from Table1 t1 join table_2 t2 where t1.parent_id= :parentId")
public List<CustomDTO>findByParentId(Long parentId){
public interface CustomDTO{
private Long table1Id;
private String name;
private String email;
}
Related
I want to join column without object reference. is that possible?
I want to do foreign key without object reference like that
#Data
#Entity
#Table(name = "HRM_EMPLOYEE_SALARY_INCREMENT")
public class EmployeeSalaryIncrement implements Serializable {
private static final long serialVersionUID = 9132875688068247271L;
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name="ID")
private Integer id;
#Column(name = "REFERENCE_NO")
private String referenceNo;
#ManyToOne
#JoinColumn(name = "AUTHORITY", referencedColumnName = "id")
private Integer authority;
#ManyToOne
#JoinColumn(name = "PART_TWO_REGISTER_ID")
private Integer partTwoRegisterId;
#Column(name = "PART_TWO_ORDER_NO")
private String partTwoOrderNo;
#Column(name = "REMARKS")
private String remarks;
#Column(name = "HRM_TYPE")
private Integer hrmType;
}
If I found solve this problem, it will helpful for me.
Joining is not needed in this case. If you only need the foreign key value, then simply add the column as a #Column like any other:
#Data
#Entity
#Table(name = "HRM_EMPLOYEE_SALARY_INCREMENT")
public class EmployeeSalaryIncrement implements Serializable {
private static final long serialVersionUID = 9132875688068247271L;
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name="ID")
private Integer id;
#Column(name = "AUTHORITY")
private Integer authority;
// other fields
// ...
}
No, I don't think that you can join columns between two entities without adding the reference of one to the related entity. You will have to create one entity class corresponding to each of your relational database table and add the reference of one to the other to establish relation.
However, I understand that you may not need all the attributes from your related table based upon your use case, and only wish to select one column from it. You can do that either by only adding required attributes in your joined table entity class (if you are sure you won't need other attributes for that table anywhere else).
Or you can use custom queries using JPQL in your repository class which selects only the required attributes from the tables that you have joined.
I will show you an example of the second way:
//Say, this is your entity class where you wish to join other table to fetch only one attribute from the joined table-
#Entity
#Table(name = "TABLE1", schema = "SCHEMA1")
public class Table1 {
#Id
#Column(name = "ID")
private String id;
#Column(name = "TABLE2_COLUMN")
private String table2Column;
#ManyToOne(fetch = FetchType.EAGER)
#JoinColumn(name = "TABLE2_COLUMN1")
private Table2 table2; //refrence of the joined table entity object
}
// And this is the joined table entity class
#Entity
#Table(name = "TABLE2", schema = "SCHEMA1")
public class Table2 {
#Id
#Column(name = "ID")
private String id;
#Column(name = "TABLE2_COLUMN1")
private String table2Column1;
#Column(name = "TABLE2_COLUMN2")
private String table2Column2; // The column which we want to select from the joined table
}
In your repository class -
#Repository
public interface Table1Repository extends JpaRepository<Table1, String> {
#Query("SELECT t1 FROM Table1 t1 WHERE t1.id = :id")
public List<Table1> getTable1Rows(#Param("id") String id);
#Query("SELECT t1.table2.table2Column2 FROM Table1 t1 WHERE t1.id = :id")
public String getTable2Column2(#Param("id") String id);
}
Based upon the response from Markus Pscheidt below, I agree when he said there's no need to join the entities if you only need the attribute which is a foreign key. As foreign key is already present as an attribute in your entity (or table) you are working with.
If you need to fetch any other column apart from foreign key, then you may use JPQL to fetch the exact column that you wish to select.
I'm trying to build the relationship between two tables using spring-data jpa. I have read many SO articles like 1, 2 but they are pretty old and don't seem to apply to my specific use case. Hence this question:
There are 2 tables user_client_scopes and scopes listed below.
user_client_scopes:
user_id (long),
client_id (string)
last_updated (timestamp)
scope_id (Foreign key to scopes table),
primary key (user_id, client_id, scope_id)
scopes:
id (int, primary key)
name (string)
A <user_id, client_id> can have multiple scopes. Similarly, the same scope can be held by many <user_id, client_id>s. Hence the many-to-many relationship. The join table (as defined by spring-data-jpa) is kind of embedded within user_client_scope table.
Here is a half-written-code:
#Entity
#Table(name = "user_client_scopes")
#RequiredArgsConstructor
#IdClass(UserClientScopesPK.class)
public class UserClientScopes implements Serializable {
#Id
#Column(name = "user_id")
private long userId;
#Id
#Column(name = "client_id")
private String clientId;
#Column(name = "last_updated")
private Timestamp lastUpdated;
#Id
#Column(name = "scope_id")
private int scopeId;
#ManyToMany // <- how to complete this definition?
private Set<Scope> scopes;
getters and setters.
Here are 2 other classes (for the sake of completion).
#Data
#RequiredArgsConstructor
public class UserClientScopesPK implements Serializable {
private long userId;
private String clientId;
private int scopeId;
}
#Entity
#Table(name = "scopes")
#RequiredArgsConstructor
public class Scope implements Serializable {
#Id
#GeneratedValue
private long id;
private String name;
}
How do I complete the user_client_scopes entity such that we can:
Find all scopes for a given <user_id, client_id>. i.e. execute the following SQL:
select user_id, client_id, scope
from scopes
join user_client_scopes ucs on ucs.scope_id = scopes.id
where ucs.user_id = ? and ucs.client_id = ?
Save new scopes for a given <user_id, client_id>. i.e. execute the following SQL:
insert into user_client_scopes (user_id, client_id, scope_id, last_updated)
select ?, ?, id, now()
from scopes
where scopes.name = ?
UPDATE 1:
Changing title to Many to one instead of Many to many relationship.
That's not a many-to-many because the association scope is mapped by the column scope_id in user_client_scopes. This means that if I take a single row in the table user_client_scopes, it will be associated to only a single row in the table scopes. Therefore, this is a many-to-one.
If the three columns <user_id, client_id, scope_id> form the key for user_client_scopes, then the mapping for the table should look like:
Entity
#Table(name = "user_client_scopes")
#RequiredArgsConstructor
#IdClass(UserClientScopesPK.class)
public class UserClientScopes implements Serializable {
#Id
#Column(name = "user_id")
private long userId;
#Id
#Column(name = "client_id")
private String clientId;
#Column(name = "last_updated")
private Timestamp lastUpdated;
#Id
#ManyToOne
#JoinedColumn(name = "scope_id")
private Scope scope;
getters and setters.
}
class UserClientScopesPK implements Serializable {
private long userId;
private String clientId;
private Scope scope;
// getters,setters, equals and hascode
}
With this mapping you can run the following HQL:
select ucs
from UserClientScopes ucs join ucs.scope
where ucs.userId = :userId and ucs.clientId = :clientId
It will return all UserClientScopes entities matching the selected pair <userId, clientId>. Each one with a different scope.
Or, if you only care about the scope:
select s
from UserClientScopes ucs join ucs.scope s
where ucs.userId = :userId and ucs.clientId = :clientId
With Spring Data JPA, it will look like this:
#Query("select s from UserClientScopes ucs join ucs.scope swhere ucs.userId = ?1 and ucs.clientId = ?2")
public List<Scope> findScopesByUserIdAndClientId(long userId, String clientId);
or
#Query("select s.name from UserClientScopes ucs join ucs.scope swhere ucs.userId = ?1 and ucs.clientId = ?2")
public List<String> findScopesNameByUserIdAndClientId(long userId, String clientId);
You can also run the insert query as native SQL (you can probably run something similar as HQL, but I don't remember the right syntax now. I will update the answer later).
One last thing, to keep track of the last updated time, you could use Spring Entity callback listener:
#Entity
...
#EntityListeners(AuditingEntityListener.class)
public class UserClientScopes implements Serializable {
#LastModifiedDate
#Column(name = "last_updated")
private Date lastUpdated;
}
When I use jpa's #OneToOne annotation, I want to get the userName field from the table, not all fields. What should I do instead?
#Setter
#Getter
#Entity
public class Menu implements Serializable {
private static final long serialVersionUID = 4462798713783196961L;
/**
* id
*/
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
...
#OneToOne
#JoinColumn(name = "createUserId",referencedColumnName = "userId")
private User createUser;
#Column(nullable = false)
private LocalDateTime createTime;
}
What do I need to do, can I get the userName field in the User object, but not all of it? Thank you in advance.
You can create a POJO with required fields. e.g. You only want id from Menu and userName from User:
public class CustomMenu {
private Long menuId;
private String userName;
public CustomMenu(Long menuId, String userName) {
this.menuId = menuId;
this.userName = userName;
}
// getters, setters
}
Then you can write a query with hql using the constructor in the CustomMenu with parameters new com.yourpackage.CustomMenu(m.id, m.createUser.userName) and join User entity (join m.createUser) :
TypedQuery<CustomMenu> query = entityManager.createQuery("select new com.yourpackage.CustomMenu(m.id, m.createUser.userName)"
+ "from com.yourpackage.Menu m join m.createUser", CustomMenu.class);
List<CustomMenu> menus = query.getResultList();
This generates one sql query with inner join fetching only required fields :
select menu0_.id as col_0_0_, user1_.user_name as col_1_0_ from menu menu0_ inner join user user1_ on menu0_.create_user_id=user1_.user_id
I have the following Entities:
#Entity
public class Organisation {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private long id;
// ...
}
#Entity
public class Section{
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private long id;
// ...
#ManyToOne
#JoinColumn(name = "organisation_id", nullable = false)
private Organisation organisation;
}
#Entity
public class SubSection {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
// ...
#ManyToOne
#JoinColumn(name = "section_id")
private Section section;
}
Now I want to find all SubSections by Organisation Id. Right now I am doing it using JPQL at the SubSectionRepository as above:
public interface SubSectionRepository extends JpaRepository<SubSection, Long>{
#Query(value = "SELECT ss.* FROM sub_section as ss INNER JOIN section as s ON ss.section_id = s.id WHERE s.organisation_id = ?1", nativeQuery = true)
List<SubSection> findByOrganisation(Long organisationId);
}
Is there any way that I can make INNER JOIN using the JpaRepository interface?
Did you try this way
subsectionRepository.findBySectionOrganizationId(long organizationId)
Update your method to
public interface SubSectionRepository extends JpaRepository<SubSection, Long> {
List<SubSection> findBySectionOrganisationId(Long organisationId);
}
Hibernate will generate something like this.
select subsec.*,
from sub_section subsec
left outer join section sec on subsection.section_id=sec.id
left outer join organisation org on section.organisation_id=org.id
where org.id=?
Don't worry about the left join term. It is actually a inner join because you have a where condition with id = on the most right table. Because of that, it effectively becomes a inner join. I.e if there is no record on the right table for that record, it will be ignored.
public class Trader {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private long id;
public String name;
public String title;
public String email;
public String phone;
public String address;
#OneToMany
public Set<Trader> customers;
}
I need an auto generated query method to search among customers names of a given trader.
Sql query is :
SELECT trader.name FROM trader WHERE trader.id IN
(SELECT * FROM trader AS t
INNER JOIN trader_customers AS tc ON tc.trader_id = t.id
WHERE t.id = 'Trader ID')
Need somethin like
findInCustomersByName(#Param("trader") Trader trader, #Param("name") String name)
You can use simple JPQL like
"select t.customers from Trade t where t.name= :name"
It gives you a list of Trade Objects and then get names of the respective objects.