要使消息流正确运行，这些字段是必需的。
These fields are required for the flow to function correctly.
如果在DB 2中建立了查找表来保存字段的值的有限集，那么这对于该字段是必需的。
This was necessary for fields where lookup tables were established in DB2 to hold the limited set of values for that field.
但是，当某个输入字段是必需的，或者由于该字段是必需的而应该设置为缺省值时，您不应该删除该字段。
However, you should not remove an input field when the field is required or should be set to a default value because the field is required.
因此，您可以看到，在JSF 中，一些验证几乎是自动的，只要指定字段是必需的，并将字段绑定到int属性即可。
Thus, you can see that some validation is nearly automatic in JSF merely by specifying that the fields are required and binding the fields to int properties.
字段元素是模型定义的必需组成部分，因此需要在这里包括它们的道理实际上就不用多说了。
The fields element is a necessary part of the model definition, so there's not really much to say other than it needs to be there.
由于移植策略和组是工作站集合必需的字段，因此移植策略本身是存储类，而存储组包含存储系统。
As migration policy and group are the required fields for workstation collection, in migration policy itself is the storage classes, whilst storage group contains the storage system.
这可能是必需的，因为对于给定的字段，可能有多个链接的记录满足最高优先级选择标准。
This may be necessary because there may be multiple linked records that satisfy the highest priority selection criteria, for a given field.
描述这些接口的元数据定义预期的输入和属性，并能提供一些验证规则，比如字段是否是必需的。
The metadata that describes the interfaces defines expected inputs and attributes, and can provide validation rules, such as whether fields are required.
然后帮助器方法会检查组件是不是必需的字段，如果是，就输出星号。
The helper method then checks to see if the component is a required field, and if so it outputs an asterisk.
IEPD-Metadata是所有元数据字段的列表，如果它们是必需的，但是却没有，则显示为错误。
IEPD - metadata is a list of all of the metadata fields, signaling an error if they are required but absent.
第一步先看看是否存在可供粘贴的hcard—fn是hcard微格式中必需的两个字段之一。
The first step is to see if there is an hCard to paste-the fn is one of the two required fields in an hCard microformats.
大多数的元数据字段不是必需的；但是，如果您打算推非文本数据（比如PDF文件或Word 文档），内容类型是必需的。
Most of the metadata fields are not required; however, the content type is required if you intend to push non-text data such as PDF files or Word documents.
大多数的元数据字段不是必需的；但是，如果您打算推非文本数据（比如PDF文件或Word 文档），内容类型是必需的。
Most of the metadata fields are not required; however, the content type is required if you intend to push non-text data such as PDF files or Word documents.
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