Re: what is null - Mailing list pgsql-general

From Ken Godee
Subject Re: what is null
Date
Msg-id 3F2E68D8.24045.1BC331@localhost
Whole thread Raw
In response to what is null  (John Harrold <jmh17@pitt.edu>)
List pgsql-general
> i'm trying to alter a table call it 'my_table' and i'm trying to set the
> field 'my_id' to prevent null values from being inserted. when i run the
> following:
>
> ALTER TABLE my_table ALTER my_id SET NOT NULL;
>
> i get:
>
> ERROR:  ALTER TABLE: Attribute "my_id" contains NULL values
>
> so i want to find out which rows have null values so i run:
>
> my=# select my_id from my_table where my_id=NULL;
>  my_id
>  ---------
>  (0 rows)
>
>
> so this would indicate to me that there are no rows in which my_id is NULL.
> so what is preventing me from altering the table? or am i just doing
> something wrong?
>
John,
Try "my_id is null" instead of "my_id=NULL"


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