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Default Value Insertion and Integrity Constraint Checking (164)

原创 IT综合 作者:tsinglee 时间:2007-11-08 15:56:10 0 删除 编辑

Integrity constraint checking occurs after the row with a default value is inserted. For
example, a row is inserted into the emp table that does not include a
value for the employee's department number. Because no value is supplied for the
department number, Oracle inserts the deptno column's default value of 20. After
inserting the default value, Oracle checks the FOREIGN KEY integrity constraint
defined on the deptno column.

默认值的插入及完整性约束检查
1. 当一个包含默认值的行被插入之后将发生完整性约束检查 .

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