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Editor to share with you how to use sequences and triggers in Oracle to achieve ID self-increment. I hope you will gain a lot after reading this article. Let's discuss it together.

When designing the database, Oracle does not have the function of automatically assigning ID as the primary key in SQL Server, so Oracle can automatically add ID through "sequence" and "trigger".

1. Create sequence Sequence

Create sequence seq_uid increment by 1 start with 1 nomaxvalue nocycle cache 10

Where "seq_uid" represents a custom sequence name

"start with 1" indicates that the sequence value starts at 1.

"increment by 1" means that the sequence increments by 1 at a time.

How to use the sequence:

Select seq_uid.nextval ID from dual

In this way, you get the next value of the sequence, and by placing this statement in the trigger, you can achieve a function similar to ID self-increment in SQL Server.

two。 Create trigger Trigger

Create trigger tri_uid before insert on [tablename] for each row when (new. [columnname] is null) begin select seq_uid.nextval into:new. [columnname] from dual;end

Where "tri_uid" represents the name of the custom trigger

"seq_uid" represents the sequence name to be used

"[columnname]" represents the column to be self-incremented

"[tablename]" represents the data table where the self-incrementing column is to be implemented.

After reading this article, I believe you have a certain understanding of how to use sequences and triggers to achieve ID in Oracle. If you want to know more about it, welcome to follow the industry information channel. Thank you for your reading!

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