Count number of Item using Hibernate/JPA or JdbcTemplate - spring

Question

I am new to Spring/Hibernate/JPA. I have an entity class MovieEntity and MovieVersionEntity. MovieEntity has few details about the movie (like genre of movie) but MovieVersionEntity has more details about it (name, director...). So I want to count the number of movies (MovieVersionEntity) associated to the MovieEntity for the given type.
MovieEntity:
#Entity(name="MovieEntity")
#Table(name="Movie")
public class MovieEntity {
#Id
#GeneratedValue(strategy=GenerationType.IDENTITY)
#Column(name="Id")
private long id;
#Column(name="IsDeleted")
private boolean isDeleted;
#Column(name="ModifiedDate")
#Temporal(TemporalType.TIMESTAMP)
private Date modifiedDate;
#OneToOne()
#JoinColumn(name="MovieTypeId")
private MovieTypeEntity movieTypeEntity;
#OneToMany(mappedBy="movieEntity",optional = false)
private List<MovieVersionEntity> movieVersionEntity;
#Transient
//#Formula("select count(*) from movie_version mv where mv.id=id")
private int childCount;
public long getId() {
return id;
}
public void setId(long id) {
this.id = id;
}
public boolean isDeleted() {
return isDeleted;
}
public void setDeleted(boolean isDeleted) {
this.isDeleted = isDeleted;
}
public MovieTypeEntity getMovieTypeEntity() {
return movieTypeEntity;
}
public void setMovieTypeEntity(MovieTypeEntity movieTypeEntity) {
this.movieTypeEntity = movieTypeEntity;
}
public Date getModifiedDate() {
return modifiedDate;
}
public void setModifiedDate(Date modifiedDate) {
this.modifiedDate = modifiedDate;
}
public MovieVersionEntity getMovieVersionEntity() {
return movieVersionEntity;
}
public void setMovieVersionEntity(MovieVersionEntity movieVersionEntity) {
this.movieVersionEntity = movieVersionEntity;
}
public int getChildCount() {
return childCount;
}
public void setChildCount(int childCount) {
this.childCount = childCount;
}
}
MovieVersionEntity
#Entity(name = "MovieVersionEntity")
#Table(name="MovieVersion")
//#EntityListeners(AuditingEntityListener.class)
public class MovieVersionEntity {
#Id()
#GeneratedValue(strategy=GenerationType.IDENTITY)
#Column(name="MovieId")
private long movieId;
#NotBlank
#Column(name="MovieName")
private String movieName;
#NotBlank
#Column(name="DirectorName")
private String directorName;
#NotBlank
#Column(name="Description")
private String description;
#Column(name="StopDate")
#Temporal(TemporalType.TIMESTAMP)
private Date stopDate;
#Column(name="DoneWatching")
private boolean doneWatching;
#Column(name="WatchDate")
#Temporal(TemporalType.TIMESTAMP)
//#CreatedDate
private Date watchDate;
#Column(name="ModifiedDate")
#Temporal(TemporalType.TIMESTAMP)
//#LastModifiedDate
private Date modifiedDate;
#ManyToOne(optional = false)
#JoinColumn(name="Id")
private MovieEntity movieEntity;
public String getMovieName() {
return movieName;
}
public void setMovieName(String movieName) {
this.movieName = movieName;
}
public String getDirectorName() {
return directorName;
}
public void setDirectorName(String directorName) {
this.directorName = directorName;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
public Date getStopDate() {
return stopDate;
}
public void setStopDate(Date stopDate) {
this.stopDate = stopDate;
}
public boolean isDoneWatching() {
return doneWatching;
}
public void setDoneWatching(boolean doneWatching) {
this.doneWatching = doneWatching;
}
public Date getWatchDate() {
return watchDate;
}
public void setWatchDate(Date watchDate) {
this.watchDate = watchDate;
}
public Date getModifiedDate() {
return modifiedDate;
}
public void setModifiedDate(Date modifiedDate) {
this.modifiedDate = modifiedDate;
}
public long getMovieId() {
return movieId;
}
public void setMovieId(long movieId) {
this.movieId = movieId;
}
public MovieEntity getMovieEntity() {
return movieEntity;
}
public void setMovieEntity(MovieEntity movieEntity) {
this.movieEntity = movieEntity;
}
}
I have written a query but I am getting sql error for it
#Query(value = "select m.*, ct.ChildCount" +
"from (" +
"select mv.id, count(movie_id) as ChildCount " +
"from movie_version mv " +
"group by mv.id" +
") as ct join movie m " +
"on ct.id = m.id;",nativeQuery = true)
List<MovieEntity> getMoviesWithCount();
Error
com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'select mv.id, count(movie_id) as ChildCount from movie_version mv group by mv.id' at line 1
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:1.8.0_60]
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:1.8.0_60]
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:1.8.0_60]
at java.lang.reflect.Constructor.newInstance(Constructor.java:422) ~[na:1.8.0_60]
at com.mysql.jdbc.Util.handleNewInstance(Util.java:425) ~[mysql-connector-java-5.1.44.jar:5.1.44]
at
Also, I am not sure if this is a right way to do it. Is there any other way I can save the count in the Transient variable. I tried using #Formuala too, but that does not give me 0 count.
Formula:
#Formula("select count(*) from movie_version mv where mv.id=id")
This is the first time I am dealing with Transient variable and I am not sure how it maps to the entity if its not persisted in the db.

Answer 1

However, #Formula worked for me. #Transient and #Formula cannot go together. #Formula is read only so I do not have to worry about the data being persisted.
http://outbottle.com/hibernate-populating-an-unmapped-entity-field-with-count-using-formula/