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ForeignKeyConstraint

外键约束 (ForeignKeyConstraint)：Element1_ChildElement1列：Element1_Id 父表：Element1 子表：ChildElement1 删除规 …

...约束（PrimaryKeyConstraint）、外关键字约束（ForeignKeyConstraint）、惟一性约束（UniqueConstraint）、检查约束（C…

To do so, click on the Add icon, and then select the database object type Foreign Key Constraint, as shown in Figure 4c.

For example , if the DeleteRule property of the ForeignKeyConstraint is None , a parent row cannot be deleted if it has any child rows.

If the DataSet contains ForeignKeyConstraint objects , invoking the AcceptChanges method also causes the AcceptRejectRule to be enforced .

Initializes a new instance of the ForeignKeyConstraint class with the specified name, parent and child DataColumn objects .

Determines the action that occurs when the AcceptChanges or RejectChanges method is invoked on a DataTable with a ForeignKeyConstraint.

A DataRelation and ForeignKeyConstraint will be created using the Element1_Id columns from both tables .

You can also enforce data integrity in the DataSet by using the UniqueConstraint and ForeignKeyConstraint objects .