ORM Nhibernet 框架的 CRUD 操作
Nhibernet 的基本语法：
private ISession _session;
public ISession Session
{
set
{
_session = value;
}
}
public QueryCriteriaAPI(ISession session)
{
_session = session;
}
#region 语法学习
/// <summary>
/// 创建ICriteria实例
/// </summary>
/// <returns></returns>
public IList<Customer> CreateCriteria()
{
//NHibernate.ICriteria这个接口代表对一个特定的持久化类的查询。
//ISession是用来制造Criteria实例的工厂。
var crit = _session.CreateCriteria(typeof(Customer));
crit.SetMaxResults(50);
var customers = crit.List<Customer>();
return customers;
}
/// <summary>
/// 缩小结果集范围
/// </summary>
/// <returns></returns>
public IList<Customer> Narrowing()
{
//一个查询条件(Criterion)是NHibernate.ICriterion接口的一个实例。
//类NHibernate.Expression.Expression定义了获得一些内置的ICriterion类型的工厂方法。
var customers = _session.CreateCriteria(typeof(Customer))
.Add(Restrictions.Like("Firstname", "YJing%"))
.Add(Restrictions.Between("Lastname", "A%", "Y%"))
.List<Customer>();
//表达式（Expressions）可以按照逻辑分组
//IList<Customer> customers = _session.CreateCriteria(typeof(Customer))
// .Add(Restrictions.Like("Firstname", "YJ%"))
// .Add(Restrictions.Or(
// Restrictions.Eq("Lastname", "L%"),
// Restrictions.IsNull("Lastname")
// ))
// .List<Customer>();
//IList<Customer> customers = _session.CreateCriteria(typeof(Customer))
// .Add(Restrictions.In("Firstname", new string[] { "YJing", "YJingLee", "Y" }))
// .Add(Restrictions.Disjunction()
// .Add(Restrictions.IsNull("Lastname"))
// .Add(Restrictions.Eq("Lastname", "Lee"))
// .Add(Restrictions.Eq("Lastname", "xyz"))
// ).List<Customer>();
//预制的条件类型（Expression的子类）。可以直接嵌入SQL。
//{alias}是一个占位符，它将会被所查询实体的行别名所替代
//Parameter paramName = new Parameter("someName", new StringSqlType());
//IList<Customer> customers = _session.CreateCriteria(typeof(Customer))
// .Add(Expression.Sql(
// new SqlString(new object[]{
// "lower({alias}.Lastname) like lower(","Lastname",")"}), "YJing%", NHibernateUtil.String))
// .List<Customer>();
return customers;
}
/// <summary>
/// 排序Order by
/// </summary>
/// <returns></returns>
public IList<Customer> Order()
{
//使用ICriteria.Order对结果集排序,true=asc,false=desc
return _session.CreateCriteria(typeof(Customer))
.Add(Restrictions.Like("Firstname", "Y%"))
.AddOrder(new NHibernate.Criterion.Order("Lastname", true))
.AddOrder(new NHibernate.Criterion.Order("Firstname", false))
.List<Customer>();
}
#endregion
#region 实例学习
/// <summary>
/// 利用CriteriaAPI按Firstname查询顾客
/// </summary>
/// <param name="firstname"></param>
/// <returns>顾客列表</returns>
public IList<Customer> UseCriteriaAPI_GetCustomersByFirstname(string firstname)
{
//NHibernate1.2写法
//return _session.CreateCriteria(typeof(Customer))
// .Add(new NHibernate.Expression.EqExpression("Firstname", firstname))
// .List<Customer>();
//NHibernate2.0写法
//return _session.CreateCriteria(typeof(Customer))
// .Add(Expression.Eq("Firstname", firstname))
// .List<Customer>();
//使用Name封装：.Add(Restrictions.Eq("Name.Firstname", firstname))
return _session.CreateCriteria(typeof(Customer))
.Add(Restrictions.Eq("Firstname", firstname))
.List<Customer>();
}
/// <summary>
/// 利用CriteriaAPI按Firstname和Lastname查询顾客
/// </summary>
/// <param name="firstname"></param>
/// <param name="lastname"></param>
/// <returns></returns>
public IList<Customer> UseCriteriaAPI_GetCustomersByFirstnameAndLastname(string firstname, string lastname)
{
//NHibernate1.2写法
//return _session.CreateCriteria(typeof(Customer))
// .Add(new NHibernate.Expression.EqExpression("Firstname", firstname))
// .Add(new NHibernate.Expression.EqExpression("Lastname", lastname))
// .List<Customer>();
//NHibernate2.0写法
//使用Name封装：.Add(Restrictions.Eq("Firstname", firstname))
return _session.CreateCriteria(typeof(Customer))
.Add(Restrictions.Eq("Firstname", firstname))
.Add(Restrictions.Eq("Lastname", lastname))
.List<Customer>();
}
/// <summary>
/// 利用CriteriaAPI获取顾客ID大于CustomerId的顾客
/// </summary>
/// <param name="customerId">顾客ID</param>
/// <returns>顾客列表</returns>
public IList<Customer> UseCriteriaAPI_GetCutomersWithIdGreaterThan(int customerId)
{
//NHibernate1.2写法
//return _session.CreateCriteria(typeof(Customer))
// .Add(new NHibernate.Expression.GtExpression("CustomerId", customerId))
// .List<Customer>();
//NHibernate2.0写法
return _session.CreateCriteria(typeof(Customer))
.Add(Restrictions.Gt("CustomerId", customerId))
.List<Customer>();
}
#endregion
#region 事务
public IList<Customer> GetAll()
{
// 开启事物
using (ITransaction tx = _session.BeginTransaction())
{
try
{
//提交事务
tx.Commit();
return null;
}
catch (HibernateException ex)
{
// 回滚事务
tx.Rollback();
throw ex ;
}
}
}
#endregion
#region 添加、 删除、更新对象
public int Add(Customer model)
{
int id =(int) _session.Save(model);
_session.Flush();
return id;
}
public void Delete ( Customer model)
{
_session.Delete(model);
_session.Flush();
}
public void Update( Customer model)
{
// 更新
_session.Update(model);
// 更新或保存 •检查这个对象是否已经存在Session中。如果对象不在，调用Save(object)来保存。如果对象存在，检查这个对象是否改变了。 如果对象改变，调用Update(object)来更新。
//_session.SaveOrUpdate(model);
_session.Flush();
}
#endregion
#region 条件查询 (Criteria Query)
// 创建 Criteria 实例 使用ISession接口的CreateCriteria方法创建了NHibernate.ICriteria接口一个特定的持久化类的查询实例，也可以说ISession是用来制造Criteria实例的工厂
public IList<Customer> Creater()
{
ICriteria cria = _session.CreateCriteria(typeof(Customer));
cria.SetMaxResults(50);
IList<Customer> list = cria.List<Customer>();
return list;
}
// 结果集限制数据
//使用ICriteria接口提供的Add方法添加Restrictions类中约束表达式可以限制一些结果集的作用。
public IList<Customer> Norrawing()
{
IList<Customer> customers = _session.CreateCriteria(typeof(Customer))
.Add(Restrictions.Like("FirstName","y%"))// 查询 FirstName like y%
.Add(Restrictions.Eq("FirstName", "yang ")) // 查询 FirstName=Yang
.Add(Restrictions.Between("LastName","%m","_n")) // 查询 LastName between %m _n
.List<Customer>();
return customers;
}
// 结果集排序
// 使用ICriteria.Order对结果集排序，第二个参数true代表asc，false代表desc。例如下面例子查询Customer对象按FirstName降序、Lastname升序。
public IList<Customer> Orderss()
{
IList<Customer> customers = _session.CreateCriteria(typeof(Customer))
.Add(Restrictions.Like("FristName","yangming"))
.AddOrder(new Order("FirstName",false)) /// FirstName 降序排序
.AddOrder(new Order("LastName",true)) // LastName 升序排序
.List<Customer>();
return customers;
}
/*
* 条件查询同样支持关联查询、动态关联抓取(在介绍一对多，多对多关系中阐述)，投影、聚合和分组，离线(detached)查询和子查询是2.0版新增加的内容
* */
// 根据 示例查询(Query By Example)
//根据示例查询(QBE，Query By Example)是条件查询的一种特殊情况，NHibernate.Criterion.Example类根据你指定的实例创造查询条件。其典型的用法：创建一个Example实例；在Example实例上设置值；根据Example和设置NHibernate返回其对象集合。
public IList<Customer> Query()
{
Customer customer = new Customer { Firstname="yangyang", Lastname="wang"};
return _session.CreateCriteria(typeof(Customer))
.Add(Example.Create(customer))
.List<Customer>();
}
//可以自行调整Example使之更实用：
public IList<Customer> Query(Customer customer)
{
Example exa = Example.Create(customer)
.IgnoreCase()
.EnableLike()
.SetEscapeCharacter('&');
return _session.CreateCriteria(typeof(Customer))
.Add(exa)
.List<Customer>();
}
#endregion
#region 查询 NHibernate查询语言(HQL)
public IList<Customer> ListAll()
{
return _session.CreateCriteria(" from Customer ")
.List<Customer>();
}
public IList<Customer> ListAll2()
{
return _session.CreateCriteria(" From Customer as c ")
.List<Customer>();
// group by 子句
//return _session.CreateCriteria("select * from Customer group by firstname ")
//.List<Customer>();
// distinct 子句
// return _session.CreateQuery("select distinct c.Firstname from Customer c")
//.List<Customer>();
// where 子句
//return _session.CreateQuery("from Customer c where c.Firstname='YJing'")
// .List<Customer>();
// 带参数的 where 子句
// // return _session.CreateQuery("from Customer c where c.CustomerId > :cid")
//.SetInt32("cid", 1)
//.List<Customer>();
}
#endregion
#region 分页查询
ISessionFactory SessionFactory;
// 分页功能
public IList<Customer> GetAll(int currentPage, int pageSize)
{
// 获取当前 session
ISession curSession = SessionFactory.GetCurrentSession();
ICriteria cria = _session.CreateCriteria(typeof(Customer));
// 分页
var model = cria.SetFetchSize(pageSize).SetFirstResult(currentPage).List<Customer>();
return model;
}
// 分页查询
//在Nhibernate里实现分页用 SetFirstResult 和SetMaxResults实现，SetFirstResult 简单的理解就是从第几条记录开始,SetMaxResults是取几条记录
private IList<Customer> GetRecord(IList<ICriterion> queryConditions, int pageIndex, int pageSize, string orderField, bool isAscending)
{
ICriteria criteria = _session.CreateCriteria(typeof(Customer));
foreach (ICriterion cri in queryConditions)
{
criteria.Add(cri);
}
//记录总数
int skipCount = (pageIndex - 1) * pageSize;
criteria.AddOrder(new Order(orderField, isAscending));
criteria.SetFirstResult(skipCount).SetMaxResults(pageSize);
return criteria.List<Customer>();
//SQL查询
//IList<Customer> customerList = Session.CreateSQLQuery("SELECT * FROM Customer")
// .SetFirstResult(pageStart*pageLimit)
// .SetMaxResults(pageLimit)
// .SetResultTransformer(Transformers.AliasToBean<Customer>()).List<Customer>();
//return customerList;
IList<Customer> customers = _session.CreateSQLQuery("")
.SetFirstResult(pageIndex * pageSize)
.SetMaxResults(pageSize)
.SetResultTransformer (NHibernate.Transform.Transformers.AliasToBean<Customer>()).List<Customer>();
return customers;
}
#endregion