Duplicate results with Hibernate, Spring, MySQL 5.7, Lombok - mysql

Question

I have simple code like:
#Transactional(readOnly = true, timeout = 10)
public List<MyClass> findThem() {
Criteria criteria = getSession().createCriteria(MyClass.class);
#SuppressWarnings("unchecked")
List<MyClass> theList = criteria.list();
return theList;
}
When I use this for the query, I get back 942 items, with duplicated items in the list. I don't see the pattern about which ones are duplicated just yet.
If I query with DB directly, I get back 138 records. 138 is the correct number of results:
SELECT count(*) FROM theschema.MY_CLASS;
I tried using the class with and without Lombok's #EqualsAndHashCode(exclude="id") on MyClass and also just not including any equals() implementation, thinking this was the cause - but no luck.
I've recently upgraded from MySQL 5.6 to MySQL 5.7.17 but I'm still on Hibernate 4.3.8.Final and HikariCP 2.5.1. The query has no WHERE clauses or anything very complicated. It may not matter, but I'm on Spring 4.3.3.RELEASE with mysql-connector-java 5.1.39.
Any other suggestions where to look? I'm going to turn on more debug logging and take a closer look in the meantime.
Update:
I'm able to correct this with criteria.setResultTransformer(CriteriaSpecification.DISTINCT_ROOT_ENTITY); but not sure why it's now necessary.
Update 2
Here's MyClass. It has more basic properties, but I excerpted them for brevity. Some of the names are renamed for privacy reasons.
import base.domain.model.Persistable;
import lombok.Getter;
import lombok.NoArgsConstructor;
import lombok.Setter;
import org.hibernate.validator.constraints.NotEmpty;
import javax.persistence.*;
import java.math.BigDecimal;
import java.util.*;
#NoArgsConstructor
#Entity
#Table(name = "MY_CLASS")
public class MyClass implements Persistable {
#Getter
#Setter
#Id
#Column(name = "MY_CLASS_ID")
#GeneratedValue(strategy = GenerationType.AUTO)
private Integer id;
#Getter
#Setter
private ClassB classb;
#Getter
#Setter
#ManyToOne
#JoinColumn(name = "CLASS_C_ID")
private ClassC classC;
#Getter
#Setter
#Transient
private Integer daysOpen;
#Getter
#Setter
#OneToOne
#JoinColumn(name = "CLASS_D_ID")
private ClassD classD;
#Getter
#Setter
#NotEmpty
private String briefDescription;
#Getter
#Setter
#Column(length = 1000)
private String details;
#Getter
#Setter
#OneToOne
#JoinColumn(name = "COMPANY_ID")
private Company company;
#Getter
#Setter
#Transient
private BigDecimal cost;
#Getter
#Setter
#ManyToMany(cascade = {CascadeType.MERGE, CascadeType.PERSIST, CascadeType.REFRESH})
#JoinTable(name = "MY_CLASS_TAG",
foreignKey = #ForeignKey(name = "FK_MY_CLASS_TAG_REQUEST"),
joinColumns = #JoinColumn(name = "MY_CLASS_ID"),
inverseJoinColumns = #JoinColumn(name = "TAG_ID"))
private Set<Tag> tags = new HashSet<>(10);
#Getter
#Setter
#ManyToMany(cascade = {CascadeType.MERGE, CascadeType.PERSIST, CascadeType.REFRESH})
#JoinTable(name = "MY_CLASS_ASSIGNEE",
foreignKey = #ForeignKey(name = "FK_MY_CLASS_ASSIGNEE"),
joinColumns = #JoinColumn(name = "MY_CLASS_ID"),
inverseJoinColumns = #JoinColumn(name = "ASSIGNEE_ID"))
private Set<Account> assignees = new HashSet<>(0);
#Getter
#Setter
#OneToMany(cascade = CascadeType.ALL, mappedBy = "myClass")
private List<MyClassHistory> historyList = new ArrayList<>(1);
private static final long serialVersionUID = 1L;
}
Update 3:
I am also able to get the correct results using HQL (abridged) without the result transformer:
String hql = "from MyClass myClass";
Query q = getSession().createQuery(hql);
List<MyClass> myClasses = q.list();
return myClasses;
Going to compare the SQL output for each (there's a lot of output to try to understand).

Answer 1

there must be some join happening in the query, which increases resultset and hence your count,often I face similar issue, you can try to take data in Set instead of list, or observe the actual query fired in DB.