Tha table in itself dosent generate Primark Key. It generates RowID which is unique to itself and used for Oracle table Operation.

User generates key through sequence or any customized logic. But in no case you can define

Creat Table Emp (Code Number(10)constraint p_key Primary Key default Sequence.Nextval)

This kind of statement is wrong as it dosent support pseudo columns(Sequence.nextval) in Default clause.

OR mention the null or empty in The Code is Primary.


Aashish

>I mean backend wouldn't take but generate the id itself. If you'd generate then you'd decide to update it too or not.
>Cetin
>
>
>>Can't understand what you mean by ?
>>
>> surrogate IOW autogenerated ids.
>>
>>
>>Aashish
>>
>>>Take ? I said surrogate IOW autogenerated ids.
>>>Cetin
>>>
>>>>Well, primary key defined fields in Oracle dosent take empty or null values.
>>>>
>>>>Aashish
>>>>
>>>>>I believe in Oracle too you can generate surrogate primary keys.
>>>>>Cetin
>>>>>>I am mainly an Oracle guy. So it was tough for me to digest.
>>>>>>
>>>>>>Aashish
>>>>>>
>>>>>>>>Hi,
>>>>>>>>
>>>>>>>>Primary key accepts empty values. Should Primark Key behave like this ?
>>>>>>>>Am I wrong somewhere ?
>>>>>>>
>>>>>>>If a primary key is accepting an empty value it's normal. It ensures value would be unique but doesn't guarantee it wouldn't be empty. ie: For an integer PK 0 is a perfectly legal value.
>>>>>>>But if a primary key is accepting empty values then you've a problem. Keys might not be updating at all.
>>>>>>>Not empty is something you should control as well as not null.
>>>>>>>Cetin