Hibernate QBC 简单收集

Hibernate QBC

介绍:

QBC(Query By Criteria)通过 API 来检索对象

主要由 Criteria 接口、Criterion 接口和 Exception 类组成,支持在运行时动态生成查询语句。

声明

事先定义:Department Employee 两个实体类

示例

查询
List<Employee> empList = session.createCriteria(Employee.class).list();
分页
List<Employee> empList = session.createCriteria(Employee.class).setFirestResult(0).setMaxResults(4).list();
Like 查询,忽略大小写
List<Employee> empList = session.createCriteria(Employee.class)
.add(Restrictions.like("ename","a",MatchMode.ANYWHERE).ignoreCase())
.list();
between 查询
list<Employee> empList = session.createCriteria(Employee.class)
.add(Restrictions.between("hiredate",begindate,enddate))
.list();
in 查询
list<Employee> empList = session.createCriteria(Employee.class)
.add(Restrictions.in("id",new Integer[]{12,123}))
.list();
> 或 >=
list<Employee> empList = session.createCriteria(Employee.class).add(Restrictions.ge("id",123)).list();
多条件查询
list<Employee> empList = session.createCriteria(Employee.class)
.add(Restrictions.ge("id",123))
.add(Restrictions.between("hiredate",begindate,enddate))
.add(Restrictions.like("ename","a", MatchMode.ANYWHERE).ignoreCase())
.list();
排序
list<Employee> empList = session.createCriteria(Employee.class)
.addOrder(Order.desc("salary"))
.list();
统计
list<Employee> empList = session.createCriteria(Employee.class)
.setProjection(Projections.rowCount())
.add(Restrictions.eq("dept.id",20))
.list();
count 统计
list<Employee> empList = session.createCriteria(Employee.class)
.setProjection(Projection.projectionList()
.add(Projetions.property("dept.id"))
.add(Projections.rowCount())
.add(Projections.avg("salary"))
.add(Projections.max("salary"))
.add(Projections.min("salary"))
.add(Projections.sum("salary"))
.add(Projections.groupProperty("dept.id")))
.list();
非空查询
list<Employee> empList = session.createCriteria(Employee.class).add(Restrictions.isNotNull("comm")).list();

转载于:https://www.cnblogs.com/holddie/p/7236103.html

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