The nullable button should not be checked.

不应选中可空按钮（nullable button）。

youdao

Unfortunately the strongly-typed DataRow classes generated by Visual Studio do not use nullable types.

不幸的是，Visual Studio生成的强类型数据集（strongly-typed DataRow）并没有使用nullable values。

youdao

Though most Rails developers do not like to keep constraints in the database, you should consider things like nullable columns.

虽然大多数Rails开发人员都不喜欢在数据库中保留限制，但您应该考虑像空列这样的事情。

youdao