Criteria查询

                                                                    Criteria查询

1.查询所有（两种重载方式）

 

//查询部门的所有信息 @Test public void selectAllDept(){ //Criteria criteria = session.createCriteria(Dept.class); Criteria criteria = session.createCriteria("cn.happy.entity.Dept"); List<Dept> list = criteria.list(); for (Dept dept : list) { System.out.println(dept.getDeptName()); } }

 

 

 

2.带条件的查询

 

//带条件查询 @Test public void selectBy(){ Criteria criteria = session.createCriteria(Dept.class); criteria = criteria.add(Restrictions.eq("deptName", "财务部")); List<Dept> list = criteria.list(); for (Dept dept : list) { System.out.println("部门名称："+dept.getDeptName()+"\t部门编号："+dept.getDeptNo()); } }

 

 

3.关联查询 

//运用别名查询 查询部门名称为 财务部 的员工 最终定位到的是员工 所以映射员工字节码 @Test public void aliziatest(){ Criteria criteria = session.createCriteria(Emp.class); //给员工表中外键属性dept起个别名 criteria.createAlias("dept", "d"); criteria = criteria.add(Restrictions.eq("d.deptName", "财务部")); List<Emp> list = criteria.list(); for (Emp emp : list) { System.out.println("职工姓名:"+emp.getEmpName()+"\t部门名称："+emp.getDept().getDeptName()); } }

4.范围查询

//查询员工姓名是邹乐或者范子阳的员工信息 @Test public void intest(){ Criteria criteria = session.createCriteria(Emp.class); List<String> lists=new ArrayList<String>(); lists.add("邹乐"); lists.add("范子阳"); criteria=criteria.add(Restrictions.in("empName", lists)); List<Emp> list = criteria.list(); for (Emp emp : list) { System.out.println("职工姓名:"+emp.getEmpName()+"\t部门名称："+emp.getDept().getDeptName()); } }

5.字符串模式匹配

//字符串模式匹配 //查询员工姓名包含“范”的员工信息 ilike（忽略大小写） //字符串模式匹配 @Test public void stringTest(){ Criteria criteria = session.createCriteria(Emp.class); criteria=criteria.add(Restrictions.ilike("empName","%范%")); List<Emp> list = criteria.list(); for (Emp emp : list) { System.out.println("职工姓名:"+emp.getEmpName()+"\t部门名称："+emp.getDept().getDeptName()); } }

 

6.逻辑运算符

//字符串模式匹配 //查询员工编号为1，员工姓名包含“范”的员工信息 ilike（忽略大小写） //字符串模式匹配 @Test public void stringTests(){ Criteria criteria = session.createCriteria(Emp.class); Criterion criterion = Restrictions.and(Restrictions.eq("empNo", 1), Restrictions.ilike("empName","范",MatchMode.START)); criteria=criteria.add(criterion); List<Emp> list = criteria.list(); for (Emp emp : list) { System.out.println("职工姓名:"+emp.getEmpName()+"\t部门名称："+emp.getDept().getDeptName()); } }

 

 7.动态查询

//动态查询 @Test public void dongtaiTest(){ Criteria criteria = session.createCriteria("cn.happy.entity.Emp"); Emp emp=new Emp(); emp.setEmpNo(2); //emp.setEmpName("邹乐"); if(emp.getEmpName()!=null){ criteria.add(Restrictions.eq("empName", emp.getEmpName())); } if(emp.getEmpNo()!=null){ criteria.add(Restrictions.eq("empNo", emp.getEmpNo())); } List<Emp> list = criteria.list(); for (Emp emp2 : list) { System.out.println("职工姓名:"+emp2.getEmpName()+"\t部门名称："+emp2.getDept().getDeptName()); } }

 

 8.集合运算

//集合运算 @Test public void collTest(){ Criteria criteria = session.createCriteria(Dept.class); criteria.add(Restrictions.isEmpty("emps")); List<Dept> list = criteria.list(); for (Dept dept : list) { System.out.println("部门名称："+dept.getDeptName()); } }

 

 9.排序

//排序 //按员工编号进行排序 @Test public void orderByeNo(){ Criteria criteria = session.createCriteria("cn.happy.entity.Emp"); criteria = criteria.addOrder(Order.desc("empNo")); List<Emp> list = criteria.list(); for (Emp emp : list) { System.out.println("职工姓名:"+emp.getEmpName()+"\t部门名称："+emp.getDept().getDeptName()); } }

10.分页

//分页 将员工信息分页查询 每页只查询三条数据 @Test public void fenye(){ Criteria criteria = session.createCriteria(Emp.class); CountProjection count2 = Projections.count("empNo"); criteria.setProjection(count2); Integer count = ((Long)criteria.uniqueResult()).intValue(); System.out.println("总记录数:"+count); criteria.addOrder(Order.desc("empNo")); int pageSize=3; int pageIndex=2; criteria.setFirstResult((pageIndex-1)*pageSize); criteria.setMaxResults(pageSize); List<Emp> list = criteria.list(); for (Emp emp : list) { System.out.println("员工姓名："+emp.getEmpName()+"部门名称："+emp.getDept().getDeptName()); } }

 

11.DetachedCriteria查询

//DetachedCriteria查询 @Test public void detacahedCriteria(){ DetachedCriteria detachedCriteria=DetachedCriteria.forClass(Emp.class); detachedCriteria.createAlias("dept", "d"); detachedCriteria.add(Restrictions.eq("d.deptName", "财务部")); List<Emp> list = detachedCriteria.getExecutableCriteria(session).list(); for (Emp emp : list) { System.out.println(emp.getEmpName()); } }

 

转载于:https://www.cnblogs.com/hmy-1365/p/5796248.html