Question

我有一个SQL查询

select distinct e.ID, e.FIRST_NAME, e.LAST_NAME, ef.PROJECT, r.NAME
from EMPLOYEE as e
inner join [RANK] as r on r.ID = e.[RANK]
inner join [EMPLOYEE_FUNCTION_IN_PROJECT] as ef on e.ID = ef.EMPLOYEE
where ef.PROJECT
in (
    select ef.PROJECT
    from [EMPLOYEE_FUNCTION_IN_PROJECT] as ef
    group by ef.PROJECT
    having COUNT(distinct ef.EMPLOYEE) >= 3
)
and ef.[FUNCTION] = 1

现在我想转换为NHibernate查询。这就是我到目前为止所做的事情

using (ITransaction myTransaction = mySession.BeginTransaction())
{
    EmployeeDAO empDaoAlias = null;
    Employee empAlias = null;
    Group groupAlias = null;
    Project projectAlias = null;
    Rank rankAlias = null;
    EmployeeFunctionInProject efpAlias = null;

    var subquery = QueryOver.Of<EmployeeFunctionInProject>(() => efpAlias)
                    .Select(Projections.GroupProperty(
                        Projections.Property<EmployeeFunctionInProject>(e => e.Project)))
                    .Where(Restrictions.Gt(Projections.Count<EmployeeFunctionInProject>(e => e.Employee), 3));

    empList = mySession.QueryOver<Employee>(() => empAlias)
        .Inner.JoinAlias(() => empAlias.Rank, () => rankAlias)
            //.Where(Restrictions.Eq(Projections.Property<Rank>(r => r.Id), 1)) //indicate this is group leader
        .WithSubquery
            .WhereProperty(() => empAlias.Id)
            .In(subquery)
        .Select(Projections.ProjectionList()
        .Add(Projections.Property(() => empAlias.Id).WithAlias(() => empDaoAlias.Id))
        .Add(Projections.Property(() => empAlias.FirstName).WithAlias(() => empDaoAlias.FirstName))
        .Add(Projections.Property(() => empAlias.LastName).WithAlias(() => empDaoAlias.LastName))
        .Add(Projections.Property(() => ??).WithAlias(() => empDaoAlias.Project))
        .Add(Projections.Property(() => rankAlias.Name).WithAlias(() => empDaoAlias.Rank)))
        .TransformUsing(Transformers.AliasToBean<EmployeeDAO>())
        .List<EmployeeDAO>().ToList();
}

首先，我需要修改

.Add(Projections.Property(() => ??).WithAlias(() => empDaoAlias.Project))

显示项目ID

其次，查询似乎无法正常工作，有人可以帮我纠正吗？

提前致谢!!!

Answer 1

您想要实现的目标更容易：

如果您使用NH 3.3.x.x和IQueryable＆＃39;
或者如果您将选择分为两部分

但是，让我们尝试以另一种方式解决问题：如果您不打算更改基础数据库，请使用EF进行查询/报告。 CQRS 是一种常用的模式。建议使用EF进行查询（NH更新）在我们过去4 - 6年实现的项目中非常常见。

SQL查询到NHibernate查询

1 个答案: