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  • 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();
    
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  • 原文地址:https://www.cnblogs.com/holddie/p/7236103.html
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