nullable
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美
网络 可空; 可空的; 可空类型; 可为空的; 类型
双语例句
- There is one major concern regarding this second strategy: in order for it to work, you must set all non-shared columns to NULLABLE.
关于第二个策略，有一个需要重点考虑的地方：为了让它工作，必须把所有非共享列设置为NULLABLE。 - A column is derived from TypedElement, and it has properties, such as nullable and defaultValue.
列是从TypedElement派生出来的，它具有一些属性，例如nullable和defaultValue。 - 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。 - The metadata API also provides the ability to define nullable columns, establish primary keys, and set-up relationships between tables.
该元数据API还提供了定义可以为空的列的能力，并设置了表之间的关系。 - 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）。 - If the column is NULLABLE, any number of NULLs can be inserted in that column.
如果此列可以包含NULL值，就可以在此列中插入任意数量的NULL值。 - 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。 - 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hasone关系）。 - If you use a nullable VARGRAPHIC column instead, the1021-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。 - In this example, no one is allowed to update or insert into that column, which is also marked as unique and not nullable.
在本例中，不允许任何人更新或插入同样标记为唯一和不得为空的列。 - 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DB2数据库列值表示为一个个可以为空的对象的方法。 - If nullable, it will contain the NULL value.
如果可为空，它将包含NULL值。 - 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。 - Previously, the code would allow default behavior to occur when handling nullable fields.
以前，代码允许在处理可为空的域时采用缺省的行为。 - Column '% s' cannot be excluded from a vertical partition because it is neither nullable nor defined with a default value.
列''%1！''不能从垂直分区内排除，因为该列既不可为空，也没有定义默认值。 - Nullable types and null coalescing operator
可置空类型和空合并运算符 - Type the specified nullable type.
指定的可空类型。 - 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 - 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-typedDataRow）并没有使用nullablevalues。 - That represents the nullable type.
表示可空类型的。 - Invalid length specified for this nullable datatype.
为该可为空的数据类型指定的长度无效。 - A table should avoid nullable columns.
表应避免可为空的列。 - Use nullable types to represent things that exist or do not exist depending on the circumstance.
根据具体环境，使用可空类型来表示存在或不存在的事物。 - 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。 - 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。 - 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。 - A database is one of the most important places to use nullable types.
数据库是使用可空类型的最重要的地方之一。 - The pros include compact tables ( no unnecessary nullable columns), data partitions across three subclass tables and easy association with other tables using the top super class table.
优点包括数据表比较紧凑（没有不需要的可空字段），数据跨三个子类的表进行分区，容易使用超类的表与其他表进行关联。 - Newly added not nullable column ( s) are involved in the primary key or unique index ( constraint).
新添加的不可空列包含在主键或唯一索引（约束）中。 - 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；）。