Обсуждение: [SQL] empty data

> serbr=> CREATE TABLE foo (mtdata date);
> CREATE
> serbr=> \dt
>
> Database    = serbr
>  +------------------+----------------------------------+----------+
>  |  Owner           |             Relation             |   Type   |
>  +------------------+----------------------------------+----------+
>  | serbr            | foo                              | table    |
>  +------------------+----------------------------------+----------+
> serbr=> INSERT INTO foo VALUES ('');
> ERROR:  Bad date external representation
> serbr=> INSERT INTO foo VALUES ('//');
> ERROR:  Bad date external representation

 My problem arise in a more general context, where the date may not
 be available at the time of data insert/update, and the data must
 be empty.

 What can I do? (I would not like to define a my own date-type...)

 Sergio

>> serbr=> CREATE TABLE foo (mtdata date);
>> CREATE
>> serbr=> \dt
>>
>> Database    = serbr
>>  +------------------+----------------------------------+----------+
>>  |  Owner           |             Relation             |   Type   |
>>  +------------------+----------------------------------+----------+
>>  | serbr            | foo                              | table    |
>>  +------------------+----------------------------------+----------+
>> serbr=> INSERT INTO foo VALUES ('');
>> ERROR:  Bad date external representation
>> serbr=> INSERT INTO foo VALUES ('//');
>> ERROR:  Bad date external representation
>
> My problem arise in a more general context, where the date may not
> be available at the time of data insert/update, and the data must
> be empty.
>
> What can I do? (I would not like to define a my own date-type...)

Try insert into foo values (NULL);

Naturally, this is silly in the example you give since you are putting a
NULL in a single field table and therefore you might as well not put a
value in.

Hope this helps.

Stuart.


+-------------------------+--------------------------------------+
| Stuart Rison            | Ludwig Institute for Cancer Research |
+-------------------------+ University College London            |
| Tel. (0171) 878 4041    | 91 Riding House Street               |
| Fax. (0171) 878 4040    | London, W1P 8BT, UNITED KINGDOM.     |
+-------------------------+--------------------------------------+
| stuart@NOJUNK_ludwig.ucl.ac.uk [Remove NOJUNK_ for it to work] |
+----------------------------------------------------------------+

On Mon, 13 Jul 1998, Sergio Brandano wrote:

> > serbr=> CREATE TABLE foo (mtdata date);
> > CREATE
> > serbr=> INSERT INTO foo VALUES ('');
> > ERROR:  Bad date external representation

guido=> INSERT INTO foo VALUES (null);
INSERT 144906 1

Postgres doesn't like empty strings for date fields.
When using the COPY command (for loading data from a file)
null date fields should contain \N (backslash, capital N).

regards,

------------------------------------------------------------------------
// Guido Carlo Piazzi                       Accompagnatore naturalistico
// gpiazzi@nemo.it            Visitate il sito WWW.ParcoDelTicino.Pmn.It
------------------------------------------------------------------------