have doubt

Question

Hi ,

I have doubt in sql , which primary key ...can you please briefly explain about this ? I am confused in this part ...

 My question is ;

 

1. How can I find this is primary key ?

 

2. Is it possible to get NULL value in primary ? why ?

 

3. Which of the scenarios are inserted in CR_DB , CR_ARCHIVE,AND CR_ERROR ?

 

4.  Primary Key will inserted in Which DB ?

 

  Please clear these doubts ....

 

Regards,

Dinesh  

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