数据库结构更改，从主键删除了搜索路径。
Database structure change to remove search path from primary keys.
它将查询数据库，为结果的每行中的每列建立索引，并且将每个索引条目绑定到行的主键上。
It queries your database, indexes each column in each row of the result, and ties each index entry to the row's primary key.
此外，在DB 2中创建复制之前，您会希望保证每一个数据库表都具有一个主键或惟一索引。
Also, before setting up replication in DB2, you will want to ensure that every database table has a primary key or unique index.
很明显，这里并不强制使用关于主键的旧规则，那么对象数据库如何处理惟一性概念？
Clearly, the old rules regarding primary keys aren't in force here; so how does an object database deal with notions of uniqueness?
这两个数据库系统都支持主键，以及支持加速查询和约束输入的键索引。
The two database systems support primary keys, along with key indices that allow you to speed up queries and constrain input.
它综合使用了控制器名称、闭包名称以及数据库记录的主键以确保uri的惟一性。
It USES a combination of the controller name, the closure name, and the database record's primary key to make each URI unique.
同样，关系数据库中的行也是惟一的，它们由主键值标识。
Similarly, relational database rows are also unique, so long as they are identified by primary key values.
当然，从来不直接对商业关系数据库环境中视图定义主键。
Of course, primary keys are never defined directly against views in a commercial relational database environment.
如果还没有，那么需要采用某种方式使用一个数据库表(一个主键，通常是一个整数)、一个用户名(也是惟一的)、一个电子邮件地址和密码等标识每个用户。
If you don't, you need to have some way of uniquely identifying each user in a database table (a primary key, usually an integer), a username (also unique), an E-mail address, a password, etc.
模板由关于数据库的模式信息、一组表、列属性和标识行的主键构成。
A template consists of schema information about a database, a group of tables, column attributes, and the primary keys that identify rows.
复制模板包含数据库的架构信息、一组表、列属性、标识行的主键。
Replication templates contain schema information about a database, a group of tables, column attributes, and the primary keys that identify rows.
模板使用关于数据库的模式信息、一组表、列和主键定义一组主副本和一个副本集。
A template USES schema information about a database, a group of tables, columns, and primary keys to define a group of master replicates and a replicate set.
在访问数据库时，它还会利用同一主键执行join操作。
It will also make use of this same primary key to perform JOIN operations when accessing the database.
首先，您通常要具有一个映射到对应数据库表主键的(代理)对象标识符。
First, you usually want to have a (surrogate) object identifier that maps to the primary key of the corresponding database table.
这可能要归结于这一事实：原始数据库和PostgreSQL这两者均支持序列，因此主键生成策略保持完好。
This can be attributed to the fact that both the original database and PostgreSQL support sequences, so the primary key generation strategy stayed intact.
主键users_id在数据库之间并不是可以移动的。
请考虑一种典型情况：所有数据库表的主键都是Long类型的，但是列名可能不一样。
A typical example: Even if the primary key is always a Long across all database tables, the column names might be different.
ActiveRecord会为不同的任务变量使用主键和副键，它们都是作为数据库的约束而定义的。
ActiveRecord USES primary and foreign keys for a variety of tasks, and both are defined as constraints on your database.
您的数据库表也不必包含具有特定名称的特定字段：如果您没有名为id 的主键字段，也不会有什么问题。
Your database tables don't have to contain certain fields with certain names, either: If you don't have a primary key field named id, the world won't end.
进一步地指定独一的主键值（标为 @Id注释），取决于生成值的数据库。
To specify further that the unique key attribute (marked with @Id annotation) will rely on your database to generate its value.
比方说你的数据库模式中包含三个作为主键的表列，分别命名为“list _ id ”、“ListId ”和“ list _ value ”。
Say your database schema contains three primary key table columns named "list_id", "ListId", and "list_value".
用node和 node_revisions表中的数据库记录数据填充这个节点对象（node object），这个记录的主键字段值与URL 中的节点id相同。
This node object is populated with data from the database record in the node and node_revisions tables, whose primary key field value is the same as the node id in the URL.
注意，安装Sample数据库时，不会为employee表自动创建主键。
Note, when you install the Sample database, the EMPLOYEE table is not automatically assigned a primary key.
在后者的情况下，为了维护多数据库环境内由数据库生成的主键的惟一性，这些片中必须有一个片被指定用来生成这些键。
In the latter case, to maintain uniqueness of the database-generated primary key in a multi-database environment, one of the slices is designated to generate these keys.
因此，如果您依赖于数据库序列(如自动主键生成)，很有可能在一个数据库集中将出现同一个主键。
As a result, if you rely on database sequences (such as for automatic primary key generation), it's likely that an identical primary key will show up across a set of databases.
它们为ID属性使用数据库生成的主键值。
They use database-generated primary key values for the ID attribute.
任何有关系型数据库背景的人都知道主键实际上不会改变，因为要把其更改传播到外键是很昂贵的工作。
Anyone with a relational data background knows that their primary keys really shouldn't change, as it's expensive to propagate that change to foreign keys.
数据库为一个表格的主键生成值(通过扩展，为相关表生成外主键)，从而将程序从这项任务的重担中解放出来。
Having the database generate values for the primary key for a table (and by extension, any foreign key values for related tables) eliminates the burden from the application from having to do so.
在关系数据库中通常可以使用主键，它由一个自动递增特性或序列生成器生成。
It is common for relational databases to use the concept of primary keys, generated by an auto-increment feature or by a sequence generator.
了解关系数据库、数据模型、惟一键、主键、外键和表联结。
Learn about relational databases, data models, unique keys, primary keys, foreign keys, and table joins.
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