如何使用linq将两列与hibernate queryover连接

本文关键字：两列 hibernate queryover 连接 linq 何使用 | 更新日期: 2023-09-27 18:20:13

我想在select子句中连接Employee的名字和姓氏，但它给出了：

无法从新<>中确定成员f_AnonymousType0`1（名称=格式（"｛0｝｛1｝"，x.FirstName，x.LastName）

var returnData = UnitOfWork.CurrentSession.QueryOver<Employee>()
                 .OrderBy(x => x.Id).Asc
                 .SelectList(u => u.Select(x => x.Id).WithAlias(() => 
                                           businessSectorItem.id)
                                   .Select(x => new { name = string.Format("{0} {1}",
                                                x.FirstName, x.LastName) })
                                                .WithAlias(() => businessSectorItem.text))
                                   .Where(x => (x.FirstName.IsInsensitiveLike
                                                  ("%" + searchTerm + "%") ||
                                                x.LastName.IsInsensitiveLike
                                                  ("%" + searchTerm + "%")) &&
                                                  ( x.Account == null || x.Account.Id ==
                                                                           accountId))
                                  .TransformUsing(Transformers
                                                  .AliasToBean<SearchEmployeeItemDto>())
                                  .Take(limit)
                                  .List<SearchEmployeeItemDto>();

如何使用linq将两列与hibernate queryover连接

QueryOver语法如下所示：

// instead of this
.Select(x => new { name = string.Format("{0} {1}",
     x.FirstName, x.LastName) })
     .WithAlias(() => businessSectorItem.text))                                   
// we should use this
.Select(
    Projections.SqlFunction("concat", 
        NHibernateUtil.String,
        Projections.Property<Employee>(e => e.FirstName),
        Projections.Constant(" "),
        Projections.Property<Employee>(e => e.LastName)
    )).WithAlias(() => businessSectorItem.text)

我们从sql函数concat中获利。我们将Projections.SqlFunction传递到Select()语句中，并使用一些默认/基本的Projections 构建部件

或者现在更简单：

using NHibernate.Criterion;
SelectList(l => l
  .Select(x => Projections.Concat(m.FirstName, ", ", m.LastName))
  .WithAlias(() => businessSectorItem.text))
)
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