Select a child from a Parent through CriteriaQuery through subqueries - sql

Question

Does any have anyone have an idea of how i can return an distinct array of product from a ProductCategory through CriteriaQuery using subqueries! I tried these tutorial but it didn't work:
Subquery in where clause with CriteriaQuery
public String[] getProductsDistinctByName(String category) {
CriteriaBuilder builder = em.getCriteriaBuilder();
CriteriaQuery<Object[]> criteriaQuery = builder.createQuery(Object[].class);
Subquery<Productscategory> subquery =criteriaQuery.subquery(Productscategory.class);
Root productsCategory = criteriaQuery.from(Productscategory.class);
subquery.select(productsCategory.<Integer>get(Productscategory_.productscategoryid))
.where(builder.equal((productsCategory.<String>get(Productscategory_.productscategoryid)), category));
Root<Products> root = criteriaQuery.from(Products.class);
criteriaQuery.multiselect(root.get(Products_.productname)).distinct(true)
.where(builder.in(root.get("productscategoryid")).value(subquery));
List<Object[]> tupleResult = em.createQuery(criteriaQuery).getResultList();
String[] arrayProducts = new String[tupleResult.size()];
for (int i = 0; i < tupleResult.size(); i++) {
arrayProducts[i] = (String) tupleResult.get(0).toString();
}
return arrayProducts;
}
and
public String[] getProductsDistinctBySubQueriesName(String category) {
CriteriaBuilder builder = em.getCriteriaBuilder();
CriteriaQuery<Tuple> criteria = builder.createTupleQuery();
//subquery
Subquery<Integer> subqueries = criteria.subquery(Integer.class);
Root<Productscategory> productCategory = subqueries.from(Productscategory.class);
subqueries.select(productCategory.<Integer>get(Productscategory_.productscategoryid))
.where(builder.equal((productCategory.<String>get("productcatgoryname")), category));
//outerquery
Root<Products> root = criteria.from(Products.class);
criteria.multiselect(root.get(Products_.productname)).distinct(true)
.where(builder.in(root.get("productscategoryid")).value(subqueries));
List<Tuple> tupleResult = em.createQuery(criteria).getResultList();
String[] arrayProducts = new String[tupleResult.size()];
for (int i = 0; i < tupleResult.size(); i++) {
arrayProducts[i] = (String) tupleResult.get(i).get(0);
}
return arrayProducts;
}
Here is the entity
import java.io.Serializable;
import java.util.Collection;
import javax.persistence.Basic;
import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.NamedQueries;
import javax.persistence.NamedQuery;
import javax.persistence.OneToMany;
import javax.persistence.Table;
import javax.xml.bind.annotation.XmlRootElement;
import javax.xml.bind.annotation.XmlTransient;
#Entity
#Table(name = "productscategory")
#XmlRootElement
#NamedQueries({
#NamedQuery(name = "Productscategory.findAll", query = "SELECT p FROM Productscategory p"),
#NamedQuery(name = "Productscategory.findByProductscategoryid", query = "SELECT p FROM Productscategory p WHERE p.productscategoryid = :productscategoryid"),
#NamedQuery(name = "Productscategory.findByProductcatgoryname", query = "SELECT p FROM Productscategory p WHERE p.productcatgoryname = :productcatgoryname"),
#NamedQuery(name = "Productscategory.findByProductcategorycomments", query = "SELECT p FROM Productscategory p WHERE p.productcategorycomments = :productcategorycomments"),
#NamedQuery(name = "Productscategory.findByStatusid", query = "SELECT p FROM Productscategory p WHERE p.statusid = :statusid")})
public class Productscategory implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Basic(optional = false)
#Column(name = "productscategoryid")
private Integer productscategoryid;
#Basic(optional = false)
#Column(name = "productcatgoryname")
private String productcatgoryname;
#Basic(optional = false)
#Column(name = "productcategorycomments")
private String productcategorycomments;
#Basic(optional = false)
#Column(name = "statusid")
private String statusid;
#OneToMany(cascade = CascadeType.ALL, mappedBy = "productcategoryid")
private Collection<Priceitem> priceitemCollection;
#OneToMany(cascade = CascadeType.ALL, mappedBy = "productcategoryid")
private Collection<Productssupplied> productssuppliedCollection;
#OneToMany(cascade = CascadeType.ALL, mappedBy = "productscategoryid")
private Collection<Products> productsCollection;
public Productscategory() {
}
public Productscategory(Integer productscategoryid) {
this.productscategoryid = productscategoryid;
}
public Productscategory(Integer productscategoryid, String productcatgoryname, String productcategorycomments, String statusid) {
this.productscategoryid = productscategoryid;
this.productcatgoryname = productcatgoryname;
this.productcategorycomments = productcategorycomments;
this.statusid = statusid;
}
public Integer getProductscategoryid() {
return productscategoryid;
}
public void setProductscategoryid(Integer productscategoryid) {
this.productscategoryid = productscategoryid;
}
public String getProductcatgoryname() {
return productcatgoryname;
}
public void setProductcatgoryname(String productcatgoryname) {
this.productcatgoryname = productcatgoryname;
}
public String getProductcategorycomments() {
return productcategorycomments;
}
public void setProductcategorycomments(String productcategorycomments) {
this.productcategorycomments = productcategorycomments;
}
public String getStatusid() {
return statusid;
}
public void setStatusid(String statusid) {
this.statusid = statusid;
}
#XmlTransient
public Collection<Priceitem> getPriceitemCollection() {
return priceitemCollection;
}
public void setPriceitemCollection(Collection<Priceitem> priceitemCollection) {
this.priceitemCollection = priceitemCollection;
}
#XmlTransient
public Collection<Productssupplied> getProductssuppliedCollection() {
return productssuppliedCollection;
}
public void setProductssuppliedCollection(Collection<Productssupplied> productssuppliedCollection) {
this.productssuppliedCollection = productssuppliedCollection;
}
#XmlTransient
public Collection<Products> getProductsCollection() {
return productsCollection;
}
public void setProductsCollection(Collection<Products> productsCollection) {
this.productsCollection = productsCollection;
}
#Override
public int hashCode() {
int hash = 0;
hash += (productscategoryid != null ? productscategoryid.hashCode() : 0);
return hash;
}
#Override
public boolean equals(Object object) {
// TODO: Warning - this method won't work in the case the id fields are not set
if (!(object instanceof Productscategory)) {
return false;
}
Productscategory other = (Productscategory) object;
if ((this.productscategoryid == null && other.productscategoryid != null) || (this.productscategoryid != null && !this.productscategoryid.equals(other.productscategoryid))) {
return false;
}
return true;
}
#Override
public String toString() {
return "com.inventory.entity.Productscategory[ productscategoryid=" + productscategoryid + " ]";
}
}
import java.io.Serializable;
import javax.persistence.Basic;
import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.NamedQueries;
import javax.persistence.NamedQuery;
import javax.persistence.OneToMany;
import javax.persistence.Table;
import javax.xml.bind.annotation.XmlRootElement;
import javax.xml.bind.annotation.XmlTransient;
#Entity
#Table(name = "products")
#XmlRootElement
#NamedQueries({
#NamedQuery(name = "Products.findAll", query = "SELECT p FROM Products p"),
#NamedQuery(name = "Products.findByProductid", query = "SELECT p FROM Products p WHERE p.productid = :productid"),
#NamedQuery(name = "Products.findByProductname", query = "SELECT p FROM Products p WHERE p.productname = :productname"),
#NamedQuery(name = "Products.findByMarketname", query = "SELECT p FROM Products p WHERE p.marketname = :marketname"),
#NamedQuery(name = "Products.findByModelvariant", query = "SELECT p FROM Products p WHERE p.modelvariant = :modelvariant"),
#NamedQuery(name = "Products.findByManufacturer", query = "SELECT p FROM Products p WHERE p.manufacturer = :manufacturer"),
#NamedQuery(name = "Products.findByProductdescription", query = "SELECT p FROM Products p WHERE p.productdescription = :productdescription"),
#NamedQuery(name = "Products.findByStatusid", query = "SELECT p FROM Products p WHERE p.statusid = :statusid")})
public class Products implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Basic(optional = false)
#Column(name = "productid")
private Integer productid;
#Basic(optional = false)
#Column(name = "productname")
private String productname;
#Basic(optional = false)
#Column(name = "marketname")
private String marketname;
#Basic(optional = false)
#Column(name = "modelvariant")
private String modelvariant;
#Basic(optional = false)
#Column(name = "manufacturer")
private String manufacturer;
#Column(name = "productdescription")
private String productdescription;
#Basic(optional = false)
#Column(name = "statusid")
private String statusid;
#OneToMany(cascade = CascadeType.ALL, mappedBy = "productid")
private Collection<Productssupplied> productssuppliedCollection;
#JoinColumn(name = "productscategoryid", referencedColumnName = "productscategoryid")
#ManyToOne(optional = false)
private Productscategory productscategoryid;
public Products() {
}
public Products(Integer productid) {
this.productid = productid;
}
public Products(Integer productid, String productname, String marketname, String modelvariant, String manufacturer, String statusid) {
this.productid = productid;
this.productname = productname;
this.marketname = marketname;
this.modelvariant = modelvariant;
this.manufacturer = manufacturer;
this.statusid = statusid;
}
public Integer getProductid() {
return productid;
}
public void setProductid(Integer productid) {
this.productid = productid;
}
public String getProductname() {
return productname;
}
public void setProductname(String productname) {
this.productname = productname;
}
public String getMarketname() {
return marketname;
}
public void setMarketname(String marketname) {
this.marketname = marketname;
}
public String getModelvariant() {
return modelvariant;
}
public void setModelvariant(String modelvariant) {
this.modelvariant = modelvariant;
}
public String getManufacturer() {
return manufacturer;
}
public void setManufacturer(String manufacturer) {
this.manufacturer = manufacturer;
}
public String getProductdescription() {
return productdescription;
}
public void setProductdescription(String productdescription) {
this.productdescription = productdescription;
}
public String getStatusid() {
return statusid;
}
public void setStatusid(String statusid) {
this.statusid = statusid;
}
#XmlTransient
public Collection<Productssupplied> getProductssuppliedCollection() {
return productssuppliedCollection;
}
public void setProductssuppliedCollection(Collection<Productssupplied> productssuppliedCollection) {
this.productssuppliedCollection = productssuppliedCollection;
}
public Productscategory getProductscategoryid() {
return productscategoryid;
}
public void setProductscategoryid(Productscategory productscategoryid) {
this.productscategoryid = productscategoryid;
}
#Override
public int hashCode() {
int hash = 0;
hash += (productid != null ? productid.hashCode() : 0);
return hash;
}
#Override
public boolean equals(Object object) {
// TODO: Warning - this method won't work in the case the id fields are not set
if (!(object instanceof Products)) {
return false;
}
Products other = (Products) object;
if ((this.productid == null && other.productid != null) || (this.productid != null && !this.productid.equals(other.productid))) {
return false;
}
return true;
}
#Override
public String toString() {
return "com.inventory.entity.Products[ productid=" + productid + " ]";
}
}