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简介:1.查询整个映射对象所有字段Java代码//直接from查询出来的是一个映射对象，即：查询整个映射对象所有字段Stringhql=”fromUsers”;Queryquery=session.crea…

1. 查询整个映射对象所有字段

Java代码

//直接from查询出来的是一个映射对象，即：查询整个映射对象所有字段

       String hql = "from Users";           Query query = session.createQuery(hql);           List<Users> users = query.list();           for(Users user : users){               System.out.println(user.getName() + " : " + user.getPasswd() + " : " + user.getId());           }    输出结果为：    

name1 : password1 : 1

name2 : password2 : 2

name3 : password3 : 3

2.查询单个字段

Java代码

//查询单个字段

       String hql = " select name from Users";           Query query = session.createQuery(hql);           List<String> list = query.list();           for(String str : list){               System.out.println(str);           }    

输出结果为：

name1

name2

name3

3.查询其中几个字段

Java代码

//查询其中几个字段

       String hql = " select name,passwd from Users";           Query query = session.createQuery(hql);           //默认查询出来的list里存放的是一个Object数组           List<Object[]> list = query.list();           for(Object[] object : list){               String name = (String)object[0];               String passwd = (String)object[1];               System.out.println(name + " : " + passwd);           }    

输出结果为：

name1 : password1

name2 : password2

name3 : password3

4.修改默认查询结果(query.list())不以Object[]数组形式返回，以List形式返回

引用

//查询其中几个字段,添加new list(),注意list里的l是小写的。也不需要导入包，这样通过query.list()出来的list里存放的不再是默认的Object数组了，而是List集合了

   String hql = " select new list(name,passwd) from Users";     Query query = session.createQuery(hql);     //默认查询出来的list里存放的是一个Object数组，但是在这里list里存放的不再是默认的Object数组了，而是List集合了     List<List> list = query.list();     for(List user : list){         String name = (String)user.get(0);         String passwd = (String)user.get(1);         System.out.println(name + " : " + passwd);     }     /**   输出结果为：    name1 : password1   name2 : password2   name3 : password3    */

5.修改默认查询结果(query.list())不以Object[]数组形式返回，以Map形式返回

Java代码 收藏代码

//查询其中几个字段,添加new map(),注意map里的m是小写的。也不需要导入包，这样通过query.list()出来的list里存放的不再是默认的Object数组了，而是map集合了

       String hql = " select new map(name,passwd) from Users";           Query query = session.createQuery(hql);           //默认查询出来的list里存放的是一个Object数组，但是在这里list里存放的不再是默认的Object数组了，而是Map集合了           List<Map> list = query.list();           for(Map user : list){               //一条记录里所有的字段值都是map里的一个元素,key是字符串0,1,2,3....，value是字段值               //如果将hql改为：String hql = " select new map(name as username,passwd as password) from Users";,那么key将不是字符串0,1,2...了，而是"username","password"了               String name = (String)user.get("0");//get("0");是get(key),注意:0,1,2...是字符串，而不是整形               String passwd = (String)user.get("1");               System.out.println(name + " : " + passwd);           }           /**         输出结果为：          name1 : password1         name2 : password2         name3 : password3          */    

6.修改默认查询结果(query.list())不以Object[]数组形式返回，以Set形式返回,但是因为Set里是不允许有重复的元素，所以:username和password的值不能相同。只需将hql改为：String hql = ” select new set(name,passwd) from Users”;

7.修改默认查询结果(query.list())不以Object[]数组形式返回，以自定义类型返回

自定义类：

Java代码

package com.domain;

public class MyUser {

   private String username;       private String password;    

//因为：String hql = ” select new com.domain.MyUser(name,passwd) from Users”;所以必须要有接受2个参数的构造函数

   public MyUser(String username,String password){           this.username = username;           this.password = password;       }       public String getUsername() {           return username;       }       public void setUsername(String username) {           this.username = username;       }       public String getPassword() {           return password;       }       public void setPassword(String password) {           this.password = password;       }    

}

Java代码

//通过query.list()出来的list里存放的不再是默认的Object数组了,而是自定义的类MyUser,必须加包名，String hql = “from Users”;中的Users类也是必须加包名的，但是因为再Users.hbm.xml里 auto-import默认值为true（所以auto-import属性也可以不写）,自动导入了

       String hql = " select new  com.domain.MyUser(name,passwd) from Users";           Query query = session.createQuery(hql);           //默认查询出来的list里存放的是一个Object数组，但是在这里list里存放的不再是默认的Object数组了，而是MyUser对象了           List<MyUser> myUsers = query.list();           for(MyUser myUser : myUsers){               String name = myUser.getUsername();               String passwd = myUser.getPassword();               System.out.println(name + " : " + passwd);           }           /**         输出结果为：         name1 : password1         name2 : password2         name3 : password3          */    

8：条件查询

Java代码

//条件查询，参数索引值从0开始，索引位置。通过setString,setParameter设置参数

       String hql = "from Users where name=? and passwd=?";           Query query = session.createQuery(hql);           //第1种方式    

// query.setString(0, “name1”);

// query.setString(1, “password1”);

       //第2种方式           query.setParameter(0, "name1",Hibernate.STRING);           query.setParameter(1, "password1",Hibernate.STRING);           List<Users> list = query.list();           for(Users users : list){               System.out.println(users.getId());           }    

Java代码

//条件查询，自定义索引名(参数名):username,:password.通过setString,setParameter设置参数

       String hql = "from Users where name=:username and passwd=:password";           Query query = session.createQuery(hql);           //第1种方式    

// query.setString(“username”, “name1”);

// query.setString(“password”, “password1”);

       //第2种方式,第3个参数确定类型           query.setParameter("username", "name1",Hibernate.STRING);           query.setParameter("password", "password1",Hibernate.STRING);           List<Users> list = query.list();           for(Users users : list){               System.out.println(users.getId());           }    

Java代码

//条件查询,通过setProperties设置参数

       String hql = "from Users where name=:username and passwd=:password";           Query query = session.createQuery(hql);           //MyUser类的2个属性必须和:username和:password对应           MyUser myUser = new MyUser("name1","password1");           query.setProperties(myUser);           List<Users> list = query.list();           for(Users users : list){               System.out.println(users.getId());           }  

[java] view plaincopy

package com.hp.ts.bca.user.bo;

import com.hp.ts.bca.common.BaseObject;

public class StationUser extends BaseObject {

   private static final long serialVersionUID = -1175811459644997844L;     private int id;     private String username;     private String officePhone;     private String mobilePhone1;     private String officeEmail;     private Integer ifDefault;     public StationUser(int id, String username, String officePhone,             String mobilePhone1, String officeEmail, Integer ifDefault) {         super();         this.id = id;         this.username = username;         this.officePhone = officePhone;         this.mobilePhone1 = mobilePhone1;         this.officeEmail = officeEmail;         this.ifDefault = ifDefault;     }     public int getId() {         return id;     }     public void setId(int id) {         this.id = id;     }     public String getUsername() {         return username;     }     public void setUsername(String username) {         this.username = username;     }     public String getOfficePhone() {         return officePhone;     }     public void setOfficePhone(String officePhone) {         this.officePhone = officePhone;     }     public String getMobilePhone1() {         return mobilePhone1;     }     public void setMobilePhone1(String mobilePhone1) {         this.mobilePhone1 = mobilePhone1;     }     public String getOfficeEmail() {         return officeEmail;     }     public void setOfficeEmail(String officeEmail) {         this.officeEmail = officeEmail;     }     public Integer getIfDefault() {         return ifDefault;     }     public void setIfDefault(Integer ifDefault) {         if(ifDefault==null)             ifDefault=0;         else             this.ifDefault = ifDefault;     }     @Override     public int hashCode() {         final int prime = 31;         int result = 1;         result = prime * result + id;         result = prime * result                 + ((ifDefault == null) ? 0 : ifDefault.hashCode());         result = prime * result                 + ((mobilePhone1 == null) ? 0 : mobilePhone1.hashCode());         result = prime * result                 + ((officeEmail == null) ? 0 : officeEmail.hashCode());         result = prime * result                 + ((officePhone == null) ? 0 : officePhone.hashCode());         result = prime * result                 + ((username == null) ? 0 : username.hashCode());         return result;     }     @Override     public boolean equals(Object obj) {         if (this == obj)             return true;         if (obj == null)             return false;         if (getClass() != obj.getClass())             return false;         StationUser other = (StationUser) obj;         if (id != other.id)             return false;         if (ifDefault == null) {             if (other.ifDefault != null)                 return false;         } else if (!ifDefault.equals(other.ifDefault))             return false;         if (mobilePhone1 == null) {             if (other.mobilePhone1 != null)                 return false;         } else if (!mobilePhone1.equals(other.mobilePhone1))             return false;         if (officeEmail == null) {             if (other.officeEmail != null)                 return false;         } else if (!officeEmail.equals(other.officeEmail))             return false;         if (officePhone == null) {             if (other.officePhone != null)                 return false;         } else if (!officePhone.equals(other.officePhone))             return false;         if (username == null) {             if (other.username != null)                 return false;         } else if (!username.equals(other.username))             return false;         return true;     }     @Override     public String toString() {         return "StationUser [id=" + id + ", username=" + username                 + ", officePhone=" + officePhone + ", mobilePhone1="                 + mobilePhone1 + ", officeEmail=" + officeEmail                 + ", ifDefault=" + ifDefault + "]";     }  

}

[java] view plaincopy

@Override

   public PageResponse<User> getUserListByStationId(int currentPage,             int rowsPerPage, String sidx, String sord, Integer stationId) {         StringBuilder hql = new StringBuilder();         hql.append("select new com.hp.ts.bca.user.bo.StationUser(a.id,a.username,a.officePhone,a.mobilePhone1,a.officeEmail,ug.ifDefault) FROM User a, UserGroup ug WHERE a.id=ug.userId and ug.groupId=");         hql.append(stationId);         //hql.append("FROM User AS user, UserGroup AS ug WHERE user.id=ug.userId");         PageResponse<User> userList = this.groupDao.excutePage(hql.toString(),                 currentPage, rowsPerPage, sidx, sord);         return userList;     }  

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