If nullable, it will contain the null value.
如果可为空，它将包含null值。
The nullable button should not be checked.
不应选中可空按钮（nullable button）。
Nullable types and null coalescing operator
可置空类型和空合并运算符
Value types and structures can be declared nullable.
可以将值类型和结构声明为可以为空。
Table 1 spells out the rules to compute firstpos and nullable .
表1清楚地说明了计算firstpos和nullable的规则。
Note the values for name, data type, default value and Nullable.
请注意字段名、数据类型、默认值和Nullable。
The expression may be a null value if the parameter is nullable.
如果参数可为空值，则表达式可能为空值。
Counts the number of hour boundaries between two nullable dates.
对两个指定日期之间的小时边界进行计数。
Counts the number of nanosecond boundaries between two nullable dates.
对两个指定日期之间的毫微秒边界数进行计数。
Specifically, any type defined as Nullable (Of t) wasn't allowed to be optional.
特别地，定义为Nullable (OfT)的任何类型都不允许是可选的。
If the return type is non-nullable, the default CLR value for the type is returned.
如果返回类型可以为非空型，则返回类型的默认clr值。
I recently ran MoMA on SubSonic and found only one issue - a weird use of Nullable types.
最近我在SubSonic上运行了MoMA，只发现了一个问题——Nullable类型的一个奇怪应用。
Library Support for nullable types, including conversion operators and arithmetic operators.
为可空类型提供类库支持，包括转换运算符和算术运算符。
In C# you can flag a value type as a nullable type by adding ? after the type (like int? x;).
在C#中，你可以在一个允许为空的值类型后面加上一个问号（比如，int?x;）。
If you use a nullable VARGRAPHIC column instead, the 1021-byte index limitation is still true.
如果使用可空的vargraphic列，那么1021字节的索引限制仍然是对的。
Only the role field - the one that had a default value of user - passed the implicit nullable constraint.
只有role字段—其默认值为user—通过隐含的nullable约束。
If the return type of the method is nullable, the distinguished null value for the type is returned.
如果该方法的返回类型可以为空，则返回类型的突出默认空值。
Unfortunately the strongly-typed DataRow classes generated by Visual Studio do not use nullable types.
不幸的是，VisualStudio生成的强类型数据集（strongly-typed DataRow）并没有使用nullable values。
For a nullable joined column, is it better performance to do a outer join, or inner join to a "null" row?
一个空连接柱，它是更好的性能做了一个外连接，或内加入一个“空”行吗？
Other features include class invariants, non-nullable reference types, and enhanced static analysis capabilities.
其他的特性还包括类不变量、非空引用类型和加强的静态分析功能。
The DB2Types classes also provide a means to represent DB2 database column values as individual nullable objects.
db2types类型还提供了将DB 2数据库列值表示为一个个可以为空的对象的方法。
Be sure to add a constraint that allows the new field to be both blank (in the HTML form) and nullable (in the database).
注意要添加一个约束，使这个新字段同时为blank(在HTML表单中)和nullable(在数据库中)。
It's the list of field names, types, and optional additional information (like the size, nullable, etc.) that adds some complexity.
它是字段名称、类型和可选附加信息(如大小、nullable)的列表，这些可选附加信息会使名称变得比较复杂。
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。
In the lower right part of the section, set all key columns of the output link to non-nullable by selecting no in the nullable column.
在本部分的右下侧，通过选择空列上的no可将所有输出链接的关键列都设置为非空。
Incidentally you might wonder what nullable is all about; that will become clearer when I discuss processing relative XPaths in a later column.
顺便说一句，您可能想知道nullable究竟是什么；在我于以后的专栏文章中讨论相对XPath的处理之后，您就会逐渐明白了。
However ElectricityDeal had too many of its own properties. Accordingly many electricity-specific nullable columns were added to the Deal table.
但是ElectricityDeal有太多自己的属性，因此有很多电相关的可空字段加入了Deal表。
This means that a User must have an Organization associated with it when it is created (if the Organization was optional, you would use a nullable has_one relationship instead).
这就意味着一个User在创建时必须具有一个相关的Organization(如果organization是可选的，那么您就应该使用一个可以为空值的has_one关系)。
If a column in the database is marked as being nullable, then the corresponding property in the data model class created by the LINQ to SQL designer will be a nullable type.
如果数据库中的一列被标志为可空，那么数据模型类相应的属性将是一个可空的类型。
For example, when you create a nullable VARCHAR (1024) column in a Unicode database and then create an index on VARCHAR (1024) column. You will encounter the following error.
例如，在Unicode数据库中创建一个可空的VARCHAR(1024)列，然后在这个VARCHAR(1024)列上创建索引。
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