Auto Increment in SQL

Things on this page are fragmentary and immature notes/thoughts of the author. Please read with your own judgement!

http://plsql4all.blogspot.com/2014/08/auto-increment-column-in-teradata.html http://stackoverflow.com/questions/21982004/how-to-generate-automatic-number-in-teradata-sql https://forums.teradata.com/forum/enterprise/auto-increment-column

1. Be careful with batch insert if there is an auto increment column. A batch insert triggers auto increment only once rather than multiple (the number of insrted records) times unless you specifically trigger auto increment multiple times. This means that records inserted with a batch insert have the same value for the auto increment column.

Teradata SQL¶

seq_num decimal(10,0) not null generated always as identity
(start with 1 
increment by 1 
minvalue 1 
maxvalue 2147483647 
no cycle)

Oracle SQL¶

sequence.nextval

create table t as (
select ...
) 

can we add an auto increament column here? if not, first create the table and then select into ...

https://mikesmithers.wordpress.com/2015/09/20/becoming-unhinged-with-insert-all-and-sequence-nextval/