描述符也可以提供与注释相同的有关实体的元数据信息，如主键字段，以及对象之间的任何映射。
The descriptor can also provide the same metadata information about the entities as annotations, such as primary key field, and any mappings between objects.
逻辑数据模型中的每个实体都被指定了一个主键。
Each entity in the logical data model is assigned a primary key.
实体中的多个属性可以组合成一个复合的主键。
Multiple attributes in the entity may be combined to form a composite primary key.
在该测试中，我们创建了一个名为ogiscustomer的实体，它有包括主键(SRCSEQ)在内的4个成员属性。
In this test, we created a single entity named OgisCustomer, which has four member attributes including the primary key (SRCSEQ).
还可以为具有组合键的实体创建一个主键类。
You can also create a primary key class for entities that have composite keys.
注解所指定的属性是实体的主键，[stringlength(512)]指定了字符串属性的最大长度值。
The [key] annotation specifies that a property is the entity's primary key, while [StringLength (512)] specifies the maximum length of a string property.
例如，如果所有类型的账户都被指定一个AccountNumber，那么可能需要使用Account Type和Account Number一起作为Accounts实体的主键。
For example, if account Numbers are assigned across all types of accounts, account type may need to be used along with account Number to form the primary key of the accounts entity.
用名为attendee的新CMP实体bean表示关系，该bean有两个字段(如果加上主键字段则有三个)。
The relationship is represented by a new CMP entity bean called Attendee, having two fields (three if we count the primary key field).
FindByPrimaryKey：在这个方法中，其目标是使用实体bean的主键从CIMOM中返回单个OperatingSystem实例。
B. FindByPrimaryKey: in this method, the objective is to get back a single OperatingSystem instance from the CIMOM using the primary keys of an entity bean.
保存在数据存储中的每一条记录，即实体，都需要有一个主键。
Each record saved in the datastore, also called an entity, requires a primary key.
实体的主键是使该实体的一个实例区别于其他实例的一个或一组属性。
An entity's primary key is the attribute or set of attributes that distinguish one instance of the entity from another.
对应于主键等字段的变量在各个实体中重复出现。
Variables for fields such as primary keys were duplicated from entity to entity.
逻辑数据模型中实体之间的关系是通过外键来表示的，外键与引用实体的主键相关联。
Relationships between entities in the logical data model are represented through foreign keys that are associated to the primary keys of the referring entity.
在微软的分片模式中，“分片键”用于将数据映射到特定的分片上，后者就是一个数据实体的主键。
In the Microsoft sharding pattern a "sharding key" is used to map data to specific shards which is the primary key in one of the data entities.
它们由逻辑数据模型转换而来，其中实体和关系转换为表、列、主键、外键以及约束。
They are transformations of logical data model where the entities and relationships are transformed into tables, columns, primary keys, foreign keys, and constraints.
一些实体具有某些共同的属性，比如标识符(主键)，而其他属性不同，这些实体可能具有共同的超类型。
Entities that share some attributes, including an identifier (primary key), but not others may be modelled as having a common supertype.
我们还使用由组成ejb主键的值构建的主键类使得把主键指定为一个单独的实体很容易。
We also use a primary key class, constructed from the values comprising the EJB primary key, to make it easy to specify the primary key as a single entity.
如果并发事务用同样的主键更新实体bean 时，更新资料将会丢失。
That is, if concurrent transactions update an entity bean with same primary key, updates could get lost.
如果数据库中有一个未设置主键的表，那么实体数据模型工具会尝试为相应的实体推断一个键。
If the database has a table without a primary key, the entity data Model tools try to infer a key for the corresponding entity.
实体具有主键。
对于实体类，必须至少有一个成员具有此特性，并应映射到相应表或视图中的主键或唯一键。
For an entity class, at least one member must have this attribute and should be mapped to the primary key or a unique key in the corresponding table or view.
对于实体类，必须至少有一个成员具有此特性，并应映射到相应表或视图中的主键或唯一键。
For an entity class, at least one member must have this attribute and should be mapped to the primary key or a unique key in the corresponding table or view.
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