One-to-one relationship or NULL field for optional column?
一对一的关系或空字段为可选的列？
A null field descriptor is the descriptor that forms the blank division in export.
一个空白字段描述符是在输出中形成空格的描述符。
The condition that plasma breakdown on Tokmak is get enough high loop voltage and large null field region in the vacuum vessel area.
托卡马克装置产生等离子体击穿的条件是在真空室区域中达到足够大的环电压以及尽可能大的零场区。
The combined record is much easier to use-you only have to check the PICTURE field to see if it's not null (which was the result of the LEFT OUTER JOIN).
而组合的记录使用起来要容易得多—只需检查PICTURE字段，查看它是否为空(这是LEFTOUTER JOIN的结果)。
By default, a column can contain a NULL value, but if you don't want that, you can append the "NOT NULL" postfix to the field definition.
默认情况下，列可以包含null值，但是，如果不想这样，可以在字段定义中附加“NOT NULL”后缀。
And if that field is null, the comment is a top-level comment.
如果该字段为空，则这个评论是顶层评论。
The goal with validation is to avoid some simple errors, such as trying to put a NULL into a field that doesn't accept them.
验证的目标就是要避免一些简单错误，例如尝试将NULL 放入不接受这种值的字段。
An XML-type field contains a complete, well-formed, optionally schema-valid document (or null).
xml类型字段包含一个完整的、格式规范的抑或模式有效的文档(或者为空)。
For example, the default invariant condition for a field requires the field to be non-null.
例如，字段的默认不变条件要求字段不能为空。
Instead, it places a null pointer into the field.
相反，它是用空指针替代。
If the form input field is not null, set the payload you receive as the widget value, as shown in Listing 14.
如果表单输入字段不为空，将小部件的值设为接收到的负载，如清单14所示。
For example, if an order status field is' Open ', then the shipment date should be null or blank.
例如，如果一个订单的状态字段是‘Open’，那么发货日期应该为null或空白。
For items that have two paths to send, there is a null byte after the first path, and it is followed by the second path, with the pathlen field of the message being set to the total length.
对于有两个路径需要发送的项，那么在第一个路径之后有一个null字节，其后紧跟第二个路径，并且消息的pathlen字段被设置为总长度。
If a field in the prototype is "null," then that value matches against any value in the data store; otherwise, the values must match exactly.
如果原型中的字段值为“null”，则该值匹配数据存储中的任何值；否则的话，必须精确地匹配值。
Rhino always returns the value null as the result of accessing a nonexistent field.
访问不存在的字段时，Rhino总是返回值null作为结果。
Clear: Setting the reference object's referent field to null and declaring the object in the heap that the reference class referred to as finalizable.
清除：将引用对象的referent域设置为 null ，并将引用类在堆中引用的对象声明为 可结束的。
We could add validation code to the register method to determine whether the first-name field is blank or null.
我们可以在register方法中添加验证代码，以确定名字字段是否为null。
Adding new instance field or renaming an existing one will cause existing objects to have it initialized to null.
添加新的实例属性或重命名现有的实例属性时，现有的对象会把这个实例属性初始化为null。
To use null values, for example, to pass a null value for the body field in the topic DTO, we used the data types in the lsxsd.lss library, such as XSD_String or XSD_Boolean, which allow null values.
要使用null值，比如，要为主题d TO中的body字段传递一个null值，我们使用lsxsd. lss库中的数据类型(如xsd_string或XSD_Boolean)，这些类型允许使用null值。
In the quiescent state, the next field of the link node pointed to by the tail is always null; in the intermediate state, it is always non-null.
在静止状态时，尾指针指向的链接节点的next字段总为null，而在中间状态时，这个字段为非null。
If you leave a String field blank in an HTML form, it comes back to the controller in the params Map as an empty String (that is, ) instead of null.
如果在HTML表单中将String字段保留为空，paramsmap中的控制器会将其看作空string(也就是“ ”)，而不是null。
If there aren't, it sets the thread-static Stack field to null.
如果不存在，它会将线程静态Stack字段设置为空。
When you want a field to be set to null, you set its value to as attribute3 in Figure 17 shows, which is equivalent to calling MyBO.set("attribute2", null) using the Service Data Object (SDO) API.
需要将字段设置为null时，您可以将其值设置为 （如图17 中的attribute3 所示），这等效于使用ServiceDataObject (SDO) API调用MyBO.set("attribute2", null)。
This tag determines whether or not the field in the name attribute is null.
这个标签确定name属性中的字段是否为空。
If the corresponding class, field, or method is not generic, a null value is passed when calling the method.
若相应的类、字段或方法非泛型，则在调用方法时将返回null值。
If null is passed into the second parameter, the default is true (disable field).
如果向第二个参数传递null，那么此参数默认的值就是true(禁用字段)。
In cases where the field was null, we could also add a message to the FacesContext directing the associated component to return navigation to the current page.
如果该字段为null，那么还可以在FacesContext中添加一条消息，指示相关组件返回到当前页。
The WeakReference object's referent field is set to null, thereby making it not refer to the heap object any longer.
WeakReference对象的referent 域被设置为 null ，从而使该对象不再引用heap 对象。
The SoftReference object's referent field is set to null, thereby making it not refer to the heap object any longer.
SoftReference对象的referent域被设置为null，从而使该对象不再引用heap对象。
For fields without signatures, I'll just use a null value. Finally, the field type is an instance of the TypeDescription class, also shown in Listing 1.
对于没有签名的字段，将只使用null值。
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