NHibernate 有好几种数据库查询方式

时间:2021-09-14 12:56:12
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);