创建一个索引禁用的外键约束。
尽量减少表上的触发器、检查和外键约束以及生成的列。
Minimize the triggers, CHECK and foreign key constraints, and generated columns for the table.
此表由20个左右引用具有外键约束的其他表。
This table is referenced by 20 or so other tables that have foreign key constraints.
外键约束允许您定义父表和子表之间的引用完整性。
A Foreign key constraint allows you to define referential integrity between a parent and child table.
用于为外键约束禁用索引的新语句被使用alter语句添加来使用。
New syntax for disabling an index for foreign key constraint was added to use with the ALTER statement.
索引扫描实际上是对父表进行主键查找，并完成外键约束验证。
The latter is actually a primary key lookup against the parent table and constitutes the foreign key constraint verification.
要终止索引禁用的外键约束，重新创建这个参考约束，执行以下命令
To drop the foreign key constraint with index disabled and recreate this referential constraint, issue the following command
未能启用约束。一行或多行中包含违反非空、唯一或外键约束的值。
Failed to enable constraints. One or more rows contain values violating non-null, unique, or foreign-key constraints.
允许您选择通过创建外键约束来实现父表和子表之间的引用完整性。
Give you the option to implement referential integrity between parent and child tables by creating a foreign key constraint.
如果使用复制发布表，则自动会为复制代理执行的操作禁用外键约束。
If you publish a table by using replication, you automatically disable foreign key constraints for operations that replication agents perform.
这一类的开销包括检查约束验证和外键约束(参照完整性(RI))验证。
This category of overhead includes CHECK constraint verification and foreign key constraint (referential integrity (ri)) verification.
显示适当的对话框(唯一约束或外键约束)，从而允许您更改约束的属性。
When you select the type, the appropriate dialog box opens (Unique constraint or Foreign Key constraint) to help you create the constraint.
在表6中，对orders表执行insert语句失败，因为custno违背了外键约束。
In table 6, the INSERT into the Orders table fails due to a foreign key constraint violation on custno.
你不能在CREATETABLE语句中包含AS子查询子句定义一个外键约束。
You cannot define a foreign key constraint in a CREATE TABLE statement that contains an AS subquery clause.
接下来，在编辑器中选择新添加的外键约束，并使用Properties视图指定关键列。
Next, select the newly added foreign key constraint in the editor and specify the key columns using the Properties view.
如果数据集包含约束(如外键约束)，则可能导致引发异常，取决于对数据集执行操作的顺序。
If a dataset contains constraints (such as a foreign-key constraint) it is possible to cause exceptions to be thrown depending on the order of operations performed against the dataset.
此外，被truncate的表和其他表之间是不能有外键约束的，否则truncateTABLE操作会失败。
Additionally, there cannot be a foreign key constraint between the table being truncated and other tables, otherwise the truncate table operation fails.
成功地由版本11.50 .xC 7升级到11.70 .xC1之后，您可以使用以下命令，创建一个索引禁用的外键约束。
After converting successfully from version 11.50.xc7 to 11.70.xc1, you can use the following commands to create a foreign key constraint with index disabled.
但是从我们数据模型的角度来看，我们没有一个惟一的表可以用来创建我们的外键约束，就像TB_RIGHT和TB_PERSON之间那样。
But from our data model's perspective, there is no unique table we can use to create our foreign key constraint, like the one between TB_RIGHT and TB_PERSON.
显然，检查约束的使用对性能有一点小小的影响，但是外键和触发器的影响却非常大。
Clearly the use of check constraints has a minor effect on performance, but foreign keys and triggers can be extremely significant.
约束支持主键、外键、惟一和非空约束。
Constraints Supports, primary, foreign, unique, not null constraint.
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.
另外，基础结构仍然是关系型的，这使XML数据能够利用关系数据库的实用功能，比如触发器、约束和外键关系。
Plus, the fact that the infrastructure is still relational allows the XML data to leverage the proven capabilities of the relational database like triggers, constraints, and foreign key relationships.
如果在主键列上存在信息检查约束，那么应该在它们相应的外键列上指定信息检查约束。
If informational check constraints exist on the primary key column, you should explicitly specify informational check constraints on their corresponding foreign key columns. For example.
也可以使用系统编目视图来检索关于NOT NULL、惟一、主键、外键和表检查约束的信息。
You can also use the system catalog views to retrieve information about NOT NULL, unique, primary key, foreign key, and table check constraints. For example.
tabconst为每个唯一性(U)、主键(p)、外键(f)或者表检查(K)约束保持一个行db2select constname,tabname,typefrom syscat . tabconst。
Syscat.tabconst Contains a row for each unique (u), primary key (p), foreign key (f), or table check (k) constraint db2 select constname, tabname, type from syscat.tabconst.
获得外键关系约束和表名。
获得外键关系约束和表名。
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