[DERBY-1918] INCREMENT of IDENTITY column described as allowing a value of zero in reference manual

• Type: Bug
• Status: Closed
• Priority: Trivial
• Resolution: Fixed
• Affects Version/s: 10.1.3.1, 10.2.1.6, 10.2.2.0, 10.3.1.4
• Fix Version/s: 10.3.1.4
• Component/s: Documentation
• Assignee: Dag H. Wanvik
• Reporter: Dag H. Wanvik
• Created: 03/Oct/06 17:16
• Updated: 19/Oct/06 16:37
• Resolved: 19/Oct/06 13:01

Description

In the description of how INCREMENT work with IDENTITY columns, th
reference manual is out of step with the implementation in the following respect
(quote from http://db.apache.org/derby/docs/10.2/ref/rrefsqlj37836.html):

> By default, the initial value of an identity column is 1, and the
> amount of the increment is 1. You can specify non-default values for
> both the initial value and the interval amount when you define the
> column with the key words STARTS WITH and INCREMENT BY. And if you
> specify a negative number for the increment value, Derby decrements
> the value with each insert. If this value is 0, or positive, Derby
******************
> increments the value with each insert.

In fact, the implementation does not allow a value of zero, but gives
error 42Z21 (LANG_AI_INVALID_INCREMENT):

ij> create table f (i int generated by default as identity (start with 1, increment by 0), j int);

ERROR 42Z21: Invalid increment specified for identity for column 'I'. Increment cannot be zero.