NHibernate 有好几种数据库查询方式

NHibernate 有好几种数据库查询方式
1、原生SQL
var employeeQuery = Database.Session
	.CreateSQLQuery("select * from Employee where FirstName = ‘John‘")
	.AddEntity(typeof(Employee));
var employees = employeeQuery.List<Employee>();

2、Hibernate Query Language(HQL)HN自己的一条语言，简称HQL

var employeeQuery = Database.Session
	.CreateQuery("select e  from Employee as e");

var employees = Database.Session
	.CreateQuery("select e from Employee as e ")
	.List<Employee>();
//select e from Employee as e where e.Firstname = ‘John‘
var firstName = "John";
var employees = Database.Session
	.CreateQuery("select e from Employee as e where e.Firstname = ‘"
	+ firstName
	+ "‘")
	.List<Employee>();

var employeeQuery = Database.Session
	.CreateQuery("select e from Employee as e where e.Firstname = :firstName");
employeeQuery.SetParameter("firstName", "John");
var employees = employeeQuery.List<Employee>();

3、Criteria API 标准API

using (var transaction = database.Session.BeginTransaction())
{
  var employeeQuery = database.Session.CreateCriteria<Employee>();
  employeeQuery.Add(Restrictions.Eq("Firstname", "john"));
  var employees = employeeQuery.List<Employee>();
  transaction.Commit();
}

using (var transaction = database.Session.BeginTransaction())
{
  var employees = database.Session.CreateCriteria<Employee>()
  .Add(Restrictions.Eq("Firstname", "john"))
  .List<Employee>();
  transaction.Commit();
}

using (var transaction = database.Session.BeginTransaction())
{
 	var employees = database.Session.CreateCriteria<Employee>()
	.Add(Restrictions.Between("DateOfJoining", DateTime.Now.AddYears(-1), DateTime.Now))
  	.List<Employee>();
  	transaction.Commit();
}

4、The QueryOver API
var employees = Database.Session.QueryOver<Employee>()
.Where(x => x.Firstname == "John")
.List<Employee>();

var employees = Database.Session
.QueryOver<Employee>()
.Where(x => x.DateOfJoining > DateTime.Now.AddYears(-1) &&
x.DateOfJoining < DateTime.Now)
.List<Employee>();

5、LINQ
var employees = from e in Database.Session.Query<Employee>()
        where e.Firstname == "John" select e;
var employees = Database.Session.Query<Employee>()
.Where(e => e.Firstname == "John");

var employees = from e in Database.Session.Query<Employee>()
where e.DateOfJoining > DateTime.Now.AddYears(-1) &&
e.DateOfJoining < DateTime.Now
select e;
var employees = Database.Session.Query<Employee>()
.Where(e => e.DateOfJoining > DateTime.Now.AddYears(-1) &&
e.DateOfJoining < DateTime.Now);