[英]oracle sql check constraint condition met
Beginner question: Is there a way to write a check constraint that restricts data where a condition is met. 初学者问题:有没有一种方法可以写一个检查约束来限制满足条件的数据。 For instance, if I want to not allow appointment times between 1100 and 1300 on a specific day.
例如,如果我不想在特定日期允许1100至1300之间的约会时间。
ALTER TABLE appointment_info
ADD CONSTRAINT ap_time_ck CHECK (ap_time NOT BETWEEN 11 and 13);
I tried 我试过了
ALTER TABLE appointment_info
ADD CONSTRAINT ap_time_ck CHECK (ap_time NOT BETWEEN 11 and 13 AND ap_date != '02-APR-2014');
But obviously that will restrict all appointment times between 1100 and 1300 and any appointments on April 2nd. 但这显然会限制所有1100至1300之间的约会时间以及4月2日的所有约会。
That's possible solution: 那是可能的解决方案:
ALTER TABLE appointment_info
ADD CONSTRAINT ap_time_ck CHECK (not (ap_time BETWEEN 11 and 13 and ap_date = date '2014-04-02'));
I am against using this: '02-APR-2014'
because it can depend on NLS settings. 我反对使用此命令:“
'02-APR-2014'
因为它可能取决于NLS设置。
Or just change and
condition to or
in your attempt. 或者只是改变
and
条件, or
在你的尝试。 It would also work. 也可以。
ALTER TABLE appointment_info
ADD CONSTRAINT ap_time_ck CHECK (ap_time NOT BETWEEN 11 and 13 OR ap_date != '02-APR-2014');
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