临时表关联查询

User.java

package domain;

import javax.persistence.Column;
import javax.persistence.ConstraintMode;
import javax.persistence.Entity;
import javax.persistence.ForeignKey;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.OneToOne;
import javax.persistence.Table;

import org.hibernate.annotations.Formula;
import org.hibernate.annotations.NotFound;
import org.hibernate.annotations.NotFoundAction;

@Entity
@Table(name="user")
public class User {
	
	@Id
	@GeneratedValue(strategy = GenerationType.AUTO)
	@Column(name="id")
	private Long id;
	
	@Column(name="username")
	private String usrename;
	
	@Column(name="address_id")
	private Long addressId;
	
	
	@Formula(value="(select count(1) from address)")
	private Integer addressCount;
	

	public Integer getAddressCount() {
		return addressCount;
	}

	public void setAddressCount(Integer addressCount) {
		this.addressCount = addressCount;
	}

	public Long getId() {
		return id;
	}

	public void setId(Long id) {
		this.id = id;
	}

	public String getUsrename() {
		return usrename;
	}

	public void setUsrename(String usrename) {
		this.usrename = usrename;
	}

	public Long getAddressId() {
		return addressId;
	}

	public void setAddressId(Long addressId) {
		this.addressId = addressId;
	}
	
	
}

　　Address.java

package domain;

import javax.persistence.Table;
import javax.persistence.Transient;

import org.hibernate.annotations.Formula;
import org.hibernate.annotations.NotFound;
import org.hibernate.annotations.NotFoundAction;

import javax.persistence.Column;
import javax.persistence.ConstraintMode;
import javax.persistence.Entity;
import javax.persistence.ForeignKey;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.OneToOne;

@Entity
@Table(name="address")
public class Address {
	
	@Id
	@GeneratedValue(strategy = GenerationType.AUTO)
	@Column(name="id")
	private Long id;
	
	@Column(name="address_name")
	private String addressName;
	//@Formula("(select count(*) from user u where u.address_id = id) ")
	@Transient
	private Integer matchCount;
	
	@OneToOne(targetEntity=Temp.class)
	@JoinColumn(name = "id",referencedColumnName = "address_id",foreignKey =@ForeignKey(value=ConstraintMode.NO_CONSTRAINT),insertable=false,updatable=false)
	@NotFound(action=NotFoundAction.IGNORE)
	private Temp temp;
	
	public Temp getTemp() {
		return temp;
	}

	public void setTemp(Temp temp) {
		this.temp = temp;
	}

	public Integer getMatchCount() {
		return matchCount;
	}

	public void setMatchCount(Integer matchCount) {
		this.matchCount = matchCount;
	}

	public Long getId() {
		return id;
	}

	public void setId(Long id) {
		this.id = id;
	}

	public String getAddressName() {
		return addressName;
	}

	public void setAddressName(String addressName) {
		this.addressName = addressName;
	}
	
	
}

　　Temp.java

package domain;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;

import org.hibernate.annotations.Subselect;

@Entity(name="temp")
@Subselect(value="select id as userid,count(1) as usercount from user group by id")
public class Temp {
	
	@Id
	private Long userid;
	
	private Integer usercount;

	public Long getUserid() {
		return userid;
	}

	public void setUserid(Long userid) {
		this.userid = userid;
	}

	public Integer getUsercount() {
		return usercount;
	}

	public void setUsercount(Integer usercount) {
		this.usercount = usercount;
	}
	
	
}

　　Main.java

package domain;

import java.util.List;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.annotations.FilterJoinTable;
import org.hibernate.criterion.DetachedCriteria;
import org.hibernate.criterion.Projections;
import org.hibernate.criterion.Restrictions;
import org.hibernate.sql.JoinType;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.orm.hibernate5.HibernateTemplate;


public class Main {
	
	public static void main(String[] args) {
		
		ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml");
		SessionFactory sf = (SessionFactory) ctx.getBean("sessionFactory");
		HibernateTemplate t = (HibernateTemplate) ctx.getBean("hibernateTemplate");
		DetachedCriteria criteria = DetachedCriteria.forClass(Address.class);
		criteria.createCriteria("temp", JoinType.LEFT_OUTER_JOIN);
		List<Address> a = (List<Address>) t.findByCriteria(criteria);
		System.out.println(a.get(0).getTemp().getUsercount());
		
	}
}