Question

我在理解一些代码时遇到了一些麻烦。我有2个公司和公司位置。映射为：

<?xml version="1.0" encoding="utf-8"?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2">
  <class name="Core.DataTransfer.CompanyLocation,Core.DataTransfer" table="`CompanyLocation`" lazy="true">
    <id name="CompanyLocationId" column="`CompanyLocationID`" type="int">
      <generator class="native" />
    </id>
    <many-to-one name="Company" cascade="none" column="`CompanyID`" not-null="true" />
  </class>
</hibernate-mapping>

<?xml version="1.0" encoding="utf-8"?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2">
  <class name="Core.DataTransfer.Company,Core.DataTransfer" table="`Company`" lazy="true">
    <id name="CompanyId" column="`CompanyID`" type="int">
      <generator class="native" />
    </id>
    <property type="string" not-null="true" length="100" name="CompanyName" column="`CompanyName`" />
    <bag name="CompanyLocations" inverse="true" lazy="true" cascade="all">
      <key column="`CompanyID`" />
      <one-to-many class="Core.DataTransfer.CompanyLocation,Core.DataTransfer" />
    </bag>
  </class>
</hibernate-mapping>

我正在尝试使用Criteria查询进行查询，如下所示：

        public IList<CompanyLocation> GetCompanyLocations(string sortExpression)
        {
            ICriteria criteria = _session.CreateCriteria(typeof(CompanyLocation));

            if (!string.IsNullOrEmpty(sortExpression))
            {
                Sort sort = new Sort(sortExpression);
                if (!string.IsNullOrEmpty(sort.AssociationPath))
                {
                    criteria.CreateCriteria(sort.AssociationPath).AddOrder(new Order(sort.SortColumn, sort.IsAscending));
                }
//                if (!string.IsNullOrEmpty(sort.AssociationPath))
//                {
//                    criteria.CreateCriteria(sort.AssociationPath);
//                }
//                criteria.AddOrder(new Order(sort.SortColumn, sort.IsAscending));
            }
            return criteria.List<CompanyLocation>();
        }

当我调用该方法并传入sortExpression“Company.CompanyName DESC”时，Sort类将解析它，以便： AssociationPath =“公司” SortColumn =“CompanyName” IsAscending = false

未注释掉的方法中的if块有效。如果我更改为注释掉的那个，它将失败：无法解析属性：CompanyName

我无法理解原因。

Answer 1

最有可能因为CreateCriteria（）创建了一个新标准（而不是像代码所期望的那样修改原始标准）

尝试更改为

if (!string.IsNullOrEmpty(sort.AssociationPath))
{
   var criteriaCopy = criteria.CreateCriteria(sort.AssociationPath);
}
criteriaCopy.AddOrder(new Order(sort.SortColumn, sort.IsAscending));

或只是简单

if (!string.IsNullOrEmpty(sort.AssociationPath))
{
   criteria = criteria.CreateCriteria(sort.AssociationPath);
}
criteria.AddOrder(new Order(sort.SortColumn, sort.IsAscending));

NHibernate Criteria查询构建

1 个答案: