Automatically add fields to simulate ms SQL in Oracle

Automatically add fields to simulate ms SQL in Oracle

Method principle: Create a sequence corresponding to the table field, and create a trigger before insertion to get a sequence value before insertion, so as to automatically increase the column of the field without manual intervention. The created trigger is as follows:

Create or replace trigger name before
Insert on table name
For each row
Begin
Select sequence name. nextval into: New. Field name from dual;

-- If: New. Field name is null then
-- Select sequence name. nextval into: New. Field name from dual;
-- End if;
End;

After the above processing, this field will not accept manual values. If you want the field to obtain the sequence value without a value, use the following comment statement, first, judge whether the field is null.