在 Oracle 和 NHibernate 中映射长文本字符串
将 NHibernate 3.1 与 SQL Server 和 Oracle DB 一起使用，我们需要存储长度超过 4000 个字符的文本字符串。文本实际上是 XML，但这并不重要 - 我们只想将其视为原始文本。使用 SQL Server，这很容易。我们将该列声明为 NVARCHAR(MAX) 并按如下方式映射它：
<property name="MyLongTextValue" length="100000"/>
length 属性的使用告诉 NHibernate 需要一个可能长于 4000 个字符的字符串。
我一生都无法弄清楚如何在 Oracle 11g 上实现此功能。我尝试将该列声明为 XMLTYPE 和 LONG，但没有成功。在第一种情况下，我们最终会得到ORA-01461：在尝试插入行时只能绑定一个 LONG 值以插入 LONG 列。在第二种情况下，数据被正确插入，但在查询时返回为空字符串。
有谁知道如何进行这项工作？答案必须与 SQL Server 和 Oracle 兼容。我宁愿不必编写自定义扩展，例如用户类型和驱动程序子类。谢谢。
Using NHibernate 3.1 with both SQL Server and Oracle DBs, we need to store a text string that is longer than 4000 characters. The text is actually XML, but that is not important - we just want to treat it as raw text. With SQL Server, this is easy. We declare the column as NVARCHAR(MAX) and map it thusly:
<property name="MyLongTextValue" length="100000"/>
The use of the length property tells NHibernate to expect a string that may be longer than 4000 characters.
For the life of me, I cannot figure out how to make this work on Oracle 11g. I've tried declaring the column as both XMLTYPE and LONG with no success. In the first case, we end up with ORA-01461: can bind a LONG value only for insert into a LONG column when trying to insert a row. In the second case, the data is inserted correctly but comes back as an empty string when querying.
Does anyone know how to make this work? The answer has to be compatible with both SQL Server and Oracle. I'd rather not have to write custom extensions such as user types and driver subclasses. Thanks.
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您应该使用类似的内容
这应该适用于 Oracle CLOB 类型和 SqlServer NTEXT 类型。
确保模型上的属性可
为 null 处理 CLOB 时应始终使用 Oracle.DataAccess
You should use something like this
This should work with Oracle CLOB type and SqlServer NTEXT type.
Make sure the property on your model is nullable
You should always use the Oracle.DataAccess when dealing with CLOBs
对于这可能感兴趣的人，我按照 这篇文章：
在我的例子中，我使用 FluentNHibernate 设置它：
For whom this may interest, I solved my problem following the step 3 of this article:
In my case I set it with FluentNHibernate:
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