Instead, it requires the developer only to denote the attributes to be persisted and to identify the attribute to represent the object's unique identifier (or primary key).
相反,它只需要程序员将属性标记为持久性的,并识别出能代表对象唯一标识符(或者主键)的属性。
An entity's primary key is the attribute or set of attributes that distinguish one instance of the entity from another.
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。
Multiple attributes in the entity may be combined to form a composite primary key.
实体中的多个属性可以组合成一个复合的主键。
Entities that share some attributes, including an identifier (primary key), but not others may be modelled as having a common supertype.
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。
The table must match the definition of your attributes; for example, the primary database key for the equations table must be the primary key of the Persistent class as well.
表必需与属性定义匹配,例如,等式表的主数据库键必须也是 Persistent类的主键。
Products often share only a few attributes, such as a primary key, a name, a short description, and a long description.
产品常常只有很少几个共有的属性,比如主键、名称、短描述和长描述。
In this test, we created a single entity named OgisCustomer, which has four member attributes including the primary key (SRCSEQ).
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。
Make a separate table for each set of related attributes, and give each table a primary key. Each field contains at most one value from its attribute domain.
为每个相关属性的集合创建一个单独的表,并为每个表指定一个主键。每列最多包含一个来自其属性域的值。
This paper gives a availability method based on Dependency -matrix that can find all primary attributes and get primary key.
就这类问题的子类给出了一种通过依赖矩阵求出全部主属性的方法,进而得出主关键字。
If attributes do not contribute to a description of the key, then remove them to a separate table. All attributes must be directly dependent on the primary key. (Read more here).
如果一些属性跟主键扯不上关系,则将这些属性转移到一个单独的表中。所有属性必须直接依赖于主键(查看更多)。
If attributes do not contribute to a description of the key, then remove them to a separate table. All attributes must be directly dependent on the primary key. (Read more here).
如果一些属性跟主键扯不上关系,则将这些属性转移到一个单独的表中。所有属性必须直接依赖于主键(查看更多)。
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