NHibernate not-null 属性无效
我正在尝试向现有表添加一列。我向映射添加了一个属性：
<property name="SelectionId" column="selection_id" not-null="true"/>
当我打开会话时，会创建新列，但是不考虑 not-null 属性：新列可为空。
我意识到您需要在添加不可为 null 的列时指定默认值，但是 default 或 default-value 属性。
我怎样才能让它发挥作用？我必须在 SQL 中手动执行此操作吗？
顺便说一句，底层的 DBMS 是 SQLite，它对 ALTER TABLE 的支持非常有限（仅支持添加列和重命名表）...
I'm trying to add a column to an existing table. I added a property to the mapping :
<property name="SelectionId" column="selection_id" not-null="true"/>
When I open the session, the new column is created, however the not-null attribute is not taken into account : the new column is nullable.
I realize you need to specify a default value when adding a non-nullable column, but there is no default or default-value attribute for the <property> element... And anyway, I don't want a default value on this column : I want to set a specific value (0) for it on existing rows, but subsequent inserts will have to specify the value explicitly.
How can I make it work ? Do I have to do it manually in SQL ?
BTW, the underlying DBMS is SQLite, which has very limited support for ALTER TABLE (only add column and rename table are supported)...
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