SQL联盟到NHibernate标准

时间:2013-09-04 20:25:59

标签: sql hibernate nhibernate sqlite sybase

有一种方法可以将这个SQL语句转换为NHibernate Criteria吗?

(select b1.FieldA as Name, b1.FieldA as FullName from Sale b1 where b1.FieldA like '%john%' or b1.FieldA like '%john%' order by b1.Id desc)
union 
(select b2.FieldC as Name, b2.FieldD as FullName from Sale b2 where b2.FieldC like '%john%' or b2.FieldD like '%john%' order by b2.Id desc)
union 
(select c.FieldE as Name, c.FieldF as FullName from Client c where c.FieldE like '%john%' or c.FieldF like '%john%' order by c.Id desc)

我发现NHibernate不支持Unions。

2 个答案:

答案 0 :(得分:2)

尝试使用视图。它可以直接映射到NHibernate中,而不依赖于特定的数据库实现。你应该删除where子句,然后你可以针对“Name”和“FullName”构建你的NHibernate标准。

  (select b1.FieldA as Name, b1.FieldA as FullName from Sale b1 order by b1.Id desc)
  union 
  (select b2.FieldC as Name, b2.FieldD as FullName from Sale b2 order by b2.Id desc)
  union 
  (select c.FieldE as Name, c.FieldF as FullName from Client c order by c.Id desc)

答案 1 :(得分:2)

所以,我找到了两个解决方案。我单独执行每个查询,而不是结果。它就像一个联盟,但不在数据库中执行,它在内存中执行。

var b1 = Session.Query<Sale>()
            .Where(x => x.FiledA.Contains(filter) || x.FiledB.Contains(filter))
            .OrderBy(x => x.Id)
            .GroupBy(x => new { x.FiledA, x.FiledB })
            .Select(x => new Foo { FullName = x.Key.FiledA, Name = x.Key.FiledB })
            .Take(30)
            .ToList();

var b2 = Session.Query<Sale>()
            .Where(x => x.FiledC.Contains(filter) || x.FiledD.Contains(filter))
            .OrderBy(x => x.Id)
            .GroupBy(x => new {x.FiledC, x.FiledD})
            .Select(x => new Foo {FullName = x.Key.FiledC, Name = x.Key.FiledD})
            .Take(30)
            .ToList();


var c = Session.Query<Client>()
            .Where(x => x.FiledE.Contains(filter) || x.FiledF.Contains(filter))
            .OrderBy(x => x.Id)
            .GroupBy(x => new { x.FiledE, x.FiledF })
            .Select(x => new Foo { FullName = x.Key.FiledE, Name = x.Key.FiledF })
            .Take(30)
            .ToList();

return b1.Concat(b2)
         .Concat(c)
         .ToList()
         .GroupBy(x => new { x.Name, x.FullName })
         .Select(x => x.First())
         .Take(30);

OR

var b1 = Session.CreateCriteria<Sale>()
    .SetProjection(Projections.ProjectionList()
        .Add(Projections.Distinct(Projections.Property("FiledA")), "Name")
        .Add(Projections.Property("FiledB"), "FullName"))
    .Add(Restrictions.Or(Restrictions.InsensitiveLike("FiledA", filter),
        Restrictions.InsensitiveLike("FiledB", filter)))
    .AddOrder(Order.Desc("Id"))
    .SetMaxResults(30)
    .SetResultTransformer(Transformers.AliasToBean<Foo>())
    .List<Foo>();

var b2 = Session.CreateCriteria<Sale>()
    .SetProjection(Projections.ProjectionList()
        .Add(Projections.Distinct(Projections.Property("FiledC")), "Name")
        .Add(Projections.Property("FiledD"), "FullName"))
    .Add(Restrictions.Or(Restrictions.InsensitiveLike("FiledC", filter),
        Restrictions.InsensitiveLike("FiledD", filter)))
    .AddOrder(Order.Desc("Id"))
    .SetMaxResults(30)
    .SetResultTransformer(Transformers.AliasToBean<Foo>())
    .List<Foo>();

var c = Session.CreateCriteria<Client>()
    .SetProjection(Projections.ProjectionList()
        .Add(Projections.Distinct(Projections.Property("FiledE")), "Name")
        .Add(Projections.Property("FieldF"), "FullName"))
    .Add(Restrictions.Or(Restrictions.InsensitiveLike("FiledE", filter),
        Restrictions.InsensitiveLike("FieldF", filter)))
    .AddOrder(Order.Desc("Id"))
    .SetMaxResults(30)
    .SetResultTransformer(Transformers.AliasToBean<Foo>())
    .List<Foo>();

return b1.Concat(b2)
         .Concat(c)
         .ToList()
         .GroupBy(x => new {x.FullName, x.Name})
         .Select(x => x.First())
         .Take(30);