Обсуждение: Why is default value not working on insert?

I have the following table:

CREATE TABLE code_source
(
  csn_src int4 NOT NULL,
  csn_type varchar(8) NOT NULL,
  cs_code varchar(15) NOT NULL,
  cs_desc_short varchar(30),
  cs_desc_long text,
  cs_remarks varchar(20),
  cs_work_flag char(1),
  cs_status char(1),
  cs_manual_key bool NOT NULL DEFAULT false,
  cs_create timestamp NOT NULL DEFAULT now(),
  cs_live date NOT NULL,
  cs_last_mod timestamp,
  cs_expire date,
  cs_last_mod_user varchar(12),
  CONSTRAINT code_source_pkey PRIMARY KEY (csn_src, csn_type, cs_code),
  CONSTRAINT code_source_fkey FOREIGN KEY (csn_src, csn_type)
      REFERENCES code_source_name (csn_src, csn_type) MATCH SIMPLE
      ON UPDATE CASCADE ON DELETE RESTRICT
)
WITHOUT OIDS;

As you can see, cs_create is set to not null with a default value of now().

However, when I run the following insert, it errors stating cs_create can not be null.  Why is the default not working?

insert into code_source (csn_src, csn_type, cs_code, cs_desc_short, cs_desc_long, cs_remarks, cs_work_flag, cs_status, cs_manual_key, cs_create, cs_live, cs_last_mod, cs_expire, cs_last_mod_user)
values ('132', 'CODE', '49', 'Some Code', null, 'NEWCODE', null, null, false, to_date(null,'yyyymmdd'), to_date('19000101','yyyymmdd'), to_date('20040318','yyyymmdd'), to_date('99991231','yyyymmdd'), 'MSBIUSERID');
ERROR:  null value in column "cs_create" violates not-null constraint

The reason for the null being passed to to_date is this is on of almot 90k lines of data we are trying to load, and the script was built to generate this code.  Since to_date(null,'yyyymmdd') returns a null, why is the default not working?

Chris

PG 8.1.3
RH AS 4

2006/8/8, Chris Hoover <revoohc@gmail.com>:
(...)
> The reason for the null being passed to to_date is this is on of almot 90k
> lines of data we are trying to load, and the script was built to generate
> this code.  Since to_date(null,'yyyymmdd') returns a null, why is the
> default not working?

Because you're trying to explicitly insert a NULL into a column which
is specified as NOT NULL.

(If you can't change the script to output DEFAULT or the explicit
default value, the best workaraound would be to create a trigger which
converts any attempt to insert a NULL value into that column to the
intended default value).


Ian Barwick

On Tue, Aug 08, 2006 at 04:41:04PM -0400, Chris Hoover wrote:
> I have the following table:

<snip>

> The reason for the null being passed to to_date is this is on of almot 90k
> lines of data we are trying to load, and the script was built to generate
> this code.  Since to_date(null,'yyyymmdd') returns a null, why is the
> default not working?

If you try to insert a NULL into a not null column, you get an error.
To trigger the default you either need to omit the column from the
insert statement, or use the DEFAULT keyword.

Have a nice day,
--
Martijn van Oosterhout   <kleptog@svana.org>   http://svana.org/kleptog/
> From each according to his ability. To each according to his ability to litigate.

Chris Hoover wrote:
> I have the following table:
>
> CREATE TABLE code_source
> (
>   csn_src int4 NOT NULL,
>   csn_type varchar(8) NOT NULL,
>   cs_code varchar(15) NOT NULL,
>   cs_desc_short varchar(30),
>   cs_desc_long text,
>   cs_remarks varchar(20),
>   cs_work_flag char(1),
>   cs_status char(1),
>   cs_manual_key bool NOT NULL DEFAULT false,
>   cs_create timestamp NOT NULL DEFAULT now(),
>   cs_live date NOT NULL,
>   cs_last_mod timestamp,
>   cs_expire date,
>   cs_last_mod_user varchar(12),
>   CONSTRAINT code_source_pkey PRIMARY KEY (csn_src, csn_type, cs_code),
>   CONSTRAINT code_source_fkey FOREIGN KEY (csn_src, csn_type)
>       REFERENCES code_source_name (csn_src, csn_type) MATCH SIMPLE
>       ON UPDATE CASCADE ON DELETE RESTRICT
> )
> WITHOUT OIDS;
>
> As you can see, cs_create is set to not null with a default value of
> now().
>
> However, when I run the following insert, it errors stating cs_create
> can not be null.  Why is the default not working?
>
> insert into code_source (csn_src, csn_type, cs_code, cs_desc_short,
> cs_desc_long, cs_remarks, cs_work_flag, cs_status, cs_manual_key,
> cs_create, cs_live, cs_last_mod, cs_expire, cs_last_mod_user)
> values ('132', 'CODE', '49', 'Some Code', null, 'NEWCODE', null, null,
> false, to_date(null,'yyyymmdd'), to_date('19000101','yyyymmdd'),
> to_date('20040318','yyyymmdd'), to_date('99991231','yyyymmdd'),
> 'MSBIUSERID');
> ERROR:  null value in column "cs_create" violates not-null constraint
>
> The reason for the null being passed to to_date is this is on of almot
> 90k lines of data we are trying to load, and the script was built to
> generate this code.  Since to_date(null,'yyyymmdd') returns a null,
> why is the default not working?
>
> Chris
>
> PG 8.1.3
> RH AS 4
>
Defaults are set when you do not specify a value, not when you try to
set a value that violates a constraint (which is what NOT NULL  is...).
You need to have the script that generates this insert query leave that
field out.



--
erik jones <erik@myemma.com>
software development
emma(r)