测试了常用的一些HQL查询方法，具体HQL的强大可以参考：
http://docs.jboss.org/hibernate/orm/3.5/reference/zh-CN/html/queryhql.html#queryhql-casesensitivity
Java Beans:
package com.my.bean; import java.util.Date;
import java.util.Set; import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.OneToMany;
import javax.persistence.Table; @Entity
@Table(name="user")
public class User {
@Id @GeneratedValue @Column(name="user_id", nullable=false)
private long userID; @Column(name="user_name", length=100, nullable=false)
private String userName; @Column(name="create_time", nullable=false)
private Date createTime; @OneToMany(mappedBy="user", cascade=CascadeType.ALL)
private Set<UserCard> cards; public long getUserID() {
return userID;
} public void setUserID(long userID) {
this.userID = userID;
} public String getUserName() {
return userName;
} public void setUserName(String userName) {
this.userName = userName;
} public Date getCreateTime() {
return createTime;
} public void setCreateTime(Date createTime) {
this.createTime = createTime;
} public Set<UserCard> getCards() {
return cards;
} public void setCards(Set<UserCard> cards) {
this.cards = cards;
}
}
package com.my.bean; 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.Table; @Entity
@Table(name="user_card")
public class UserCard {
@Id
@GeneratedValue(strategy=GenerationType.IDENTITY)
@Column(name="card_id")
private long cardID; @Column(name="card_name")
private String cardName; @ManyToOne(cascade=CascadeType.ALL)
@JoinColumn(name="user_id")
private User user; public long getCardID() {
return cardID;
}
public void setCardID(long cardID) {
this.cardID = cardID;
}
public String getCardName() {
return cardName;
}
public void setCardName(String cardName) {
this.cardName = cardName;
}
public User getUser() {
return user;
}
public void setUser(User user) {
this.user = user;
}
}
一些DTO的Java Beans:
package com.my.bean.dto;
public class GroupByTemp {
private long sumUser;
private long userID;
public long getSumUser() {
return sumUser;
}
public void setSumUser(long sumUser) {
this.sumUser = sumUser;
}
public long getUserID() {
return userID;
}
public void setUserID(long userID) {
this.userID = userID;
}
/**
* @param sumUser
* @param userID
*/
public GroupByTemp(long sumUser, long userID) {
this.sumUser = sumUser;
this.userID = userID;
}
}
package com.my.bean.dto; import java.math.BigInteger;
import java.util.Date; public class UserSQLTemp {
private BigInteger userID;
private Date createTime;
private String userName;
public BigInteger getUserID() {
return userID;
}
public void setUserID(BigInteger userID) {
this.userID = userID;
}
public Date getCreateTime() {
return createTime;
}
public void setCreateTime(Date createTime) {
this.createTime = createTime;
}
public String getUserName() {
return userName;
}
public void setUserName(String userName) {
this.userName = userName;
}
}
package com.my.bean.dto;
public class UserTemp {
private long userID;
private String userName;
private String cardName;
public long getUserID() {
return userID;
}
public void setUserID(long userID) {
this.userID = userID;
}
public String getUserName() {
return userName;
}
public void setUserName(String userName) {
this.userName = userName;
}
public String getCardName() {
return cardName;
}
public void setCardName(String cardName) {
this.cardName = cardName;
}
public UserTemp(long userID, String userName, String cardName) {
super();
this.userID = userID;
this.userName = userName;
this.cardName = cardName;
}
}
测试：
package com.my.init; import java.util.List; import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.Transaction;
import org.hibernate.transform.Transformers; import com.my.bean.User;
import com.my.bean.UserCard;
import com.my.bean.dto.GroupByTemp;
import com.my.bean.dto.UserSQLTemp;
import com.my.bean.dto.UserTemp;
import com.my.dao.util.HibernateUtil; public class Test { @SuppressWarnings({ "unchecked" })
public static void main(String[] args) {
Session session = HibernateUtil.getSessionFactory().openSession();
Transaction tx = session.beginTransaction(); try {
// ----------------------------------------------------
// Select all data
// ----------------------------------------------------
String hql = "FROM User AS U ORDER BY U.createTime DESC";
Query query = session.createQuery(hql);
List<User> users = query.list();
for (User user : users) {
System.out.println("User:" + user.getUserName());
System.out.println("Card size:" + user.getCards().size());
for (UserCard c : user.getCards()) {
System.out.println("Card:" + c.getCardName());
}
} // ----------------------------------------------------
// Select all user name
// ----------------------------------------------------
hql = "SELECT U.userName FROM User AS U";
query = session.createQuery(hql);
List<String> userNames = query.list();
for (String item : userNames) {
System.out.println("Name:" + item);
} // ----------------------------------------------------
// Where
// ----------------------------------------------------
hql = "FROM User AS U WHERE U.userID=:userID";
query = session.createQuery(hql);
query.setParameter("userID", (long) 1);
users = query.list();
for (User user : users) {
System.out.println("User:" + user.getUserName());
} // ----------------------------------------------------
// Other fields, DTO
// ----------------------------------------------------
hql = "SELECT new com.my.bean.dto.UserTemp(U.userID, U.userName, C.cardName)"
+ " FROM User AS U, UserCard AS C"
+ " WHERE U.userID=:userID";
query = session.createQuery(hql);
query.setParameter("userID", (long) 2);
List<UserTemp> temps = query.list();
for (UserTemp item : temps) {
System.out.println("User name:" + item.getUserName()
+ "\tCard name:" + item.getCardName());
} // ----------------------------------------------------
// Group by
// ----------------------------------------------------
hql = "SELECT new com.my.bean.dto.GroupByTemp(SUM(C.user.userID), C.user.userID) FROM UserCard AS C GROUP BY C.cardName";
query = session.createQuery(hql);
List<GroupByTemp> results = query.list();
for (GroupByTemp item : results) {
System.out.println("UserID:" + item.getUserID() + "\tSum:"
+ item.getSumUser());
} // ----------------------------------------------------
// Count
// ----------------------------------------------------
hql = "SELECT COUNT(*) FROM User";
query = session.createQuery(hql);
long count = (long) query.uniqueResult();
System.out.println("Total:" + count); // ----------------------------------------------------
// SQL
// ----------------------------------------------------
String sql = "SELECT user_id AS userID, user_name AS userName, create_time AS createTime FROM user";
query = session.createSQLQuery(sql).setResultTransformer(
Transformers.aliasToBean(UserSQLTemp.class));
List<UserSQLTemp> usersTemp = query.list();
for (UserSQLTemp item : usersTemp) {
System.out.println("UserID:" + item.getUserID()
+ "\tUser name:" + item.getUserName());
} // ----------------------------------------------------
// Left join
// ----------------------------------------------------
hql = "SELECT U FROM User U LEFT JOIN U.cards C WITH C.cardID=:cardID WHERE U.userName=:userName";
query = session.createQuery(hql);
query.setLong("cardID", 1);
query.setString("userName", "Robin");
users = query.list();
for (User user : users) {
System.out.println("User ID:" + user.getUserID()
+ "\tUser name:" + user.getUserName());
} // ----------------------------------------------------
// Top N records
// ----------------------------------------------------
hql = "SELECT U FROM User AS U";
query = session.createQuery(hql).setMaxResults(1);
users = query.list();
for (User user : users) {
System.out.println("User name:" + user.getUserName());
} // ----------------------------------------------------
// Like
// ----------------------------------------------------
hql = "SELECT U FROM User AS U WHERE U.userName LIKE :userName";
query = session.createQuery(hql);
query.setString("userName", "%m%");
users = query.list();
for (User user : users) {
System.out.println("User name:" + user.getUserName());
} // ----------------------------------------------------
// Paging, set First result and Max result
// ----------------------------------------------------
hql = "SELECT U FROM User AS U";
query = session.createQuery(hql).setFirstResult(1).setMaxResults(1);
users = query.list();
for (User user : users) {
System.out.println("User name:" + user.getUserName());
} // ----------------------------------------------------
// IN
// ----------------------------------------------------
hql = "SELECT U FROM User AS U WHERE U.userID IN (:userID)";
query = session.createQuery(hql);
Long[] userIDs = new Long[] { (long) 1, (long) 2 };
query.setParameterList("userID", userIDs);
users = query.list();
for (User user : users) {
System.out.println("User name:" + user.getUserName());
} // ----------------------------------------------------
// Sub search
// ----------------------------------------------------
hql = "SELECT U FROM User AS U WHERE U IN (SELECT C.user FROM UserCard AS C WHERE C.cardID=:cardID)";
query = session.createQuery(hql);
query.setLong("cardID", 1);
users = query.list();
for (User user : users) {
System.out.println("User name:" + user.getUserName());
} // ----------------------------------------------------
// Sub case
// ----------------------------------------------------
hql = "SELECT new com.my.bean.dto.UserTemp("
+ "U.userID, U.userName, (SELECT C.cardName FROM UserCard C WHERE C.cardID=:cardID)"
+ ") FROM User U";
query = session.createQuery(hql);
query.setLong("cardID", 1);
temps = query.list();
for (UserTemp item : temps) {
System.out.println("UserID:" + item.getUserID()
+ "\tUser name:" + item.getUserName() + "\tCard name:"
+ item.getCardName());
} tx.commit();
} catch (Exception e) {
tx.rollback();
e.printStackTrace();
} session.close();
} }
HQL中也可以使用SQL，见测试例子：SQL
（但这种方法不推荐使用，因为这样就破坏了OO设计，除非在逼不得已的情况下，比如那些最初没设计好数据库然后又要出复杂到恶心的报表时）