Re: Specifying column datatypes in CTAS

Um... What about something like this?

SQL> create table tim (col1 number);

Table created.

SQL> insert into tim values (1);

1 row created.

SQL> create table tim2 as select col1, 'test' col2 from tim;

Table created.

SQL> desc tim2

 Name                                      Null?    Type
 ----------------------------------------- -------- 
----------------------------
 COL1                                               NUMBER
 COL2                                               CHAR(4)

SQL> create table tim3 as select col1, cast('test' as varchar2(100)) col2 from tim;

Table created.

SQL> desc tim3

 Name                                      Null?    Type
 ----------------------------------------- -------- 
----------------------------
 COL1                                               NUMBER
 COL2                                               VARCHAR2(100)

SQL> alter table tim3 modify (col2 not null);

Table altered.

SQL> desc tim3

 Name                                      Null?    Type
 ----------------------------------------- -------- 
----------------------------
 COL1                                               NUMBER
 COL2                                      NOT NULL VARCHAR2(100)

SQL> Mark Richard wrote:

>
>
>Hi List,
>
>I have stumbled across a problem and I am hoping there is an easy solution.
>I have to add two columns to an existing table. One of these columns is
>populated with a constant value for all existing records and the other can
>be determined using a simple DECODE on other existing columns.
>
>The table is quite large (~100 million records) and I was hoping to combine
>the activity with a rebuild into a new tablespace at the same time.
>Therefore, I figure the quickest way to achieve this is a simple "create
>table as select" type statement.
>
>My problem is specifying the datatypes, and in particular the NOT NULL
>state of the newly added columns. Working on Oracle 8.1.7.4 I get an error
>if I try something like "create table my_dual (the_col varchar2(10) not
>null) as select * from dual" - I cannot specify datatypes when using an "as
>select..." clause it seems.
>
>I realise I can name the new columns using column aliasing in the select
>clause, but I am struggling to get the length of the data type and the NOT
>NULL attribute set on the new columns.
>
>What is the best way to resolve this problem? Is there some syntax I am
>missing or do I absolutely need to create structure and then insert data?
>
>Thanks in advance,
>
>Mark.
>
>
>
>
><<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<---->>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
>Privileged/Confidential information may be contained in this message.
>If you are not the addressee indicated in this message (or responsible for delivery of the message to such person), you may not copy or deliver this message to anyone.
>In such a case, you should destroy this message and kindly notify the sender by reply e-mail or by telephone on (03) 9612-6999 or (61) 3 9612-6999.
>Please advise immediately if you or your employer does not consent to Internet e-mail for messages of this kind.
>Opinions, conclusions and other information in this message that do not relate to the official business of Transurban Infrastructure Developments Limited and CityLink Melbourne Limited shall be understood as neither given nor endorsed by them.
><<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<---->>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
>
>----------------------------------------------------------------
>Please see the official ORACLE-L FAQ: http://www.orafaq.com
>----------------------------------------------------------------
>To unsubscribe send email to: oracle-l-request_at_freelists.org
>put 'unsubscribe' in the subject line.
>--
>Archives are at http://www.freelists.org/archives/oracle-l/
>FAQ is at http://www.freelists.org/help/fom-serve/cache/1.html
>-----------------------------------------------------------------
>
>

-- 
Regards,
Tim Johnston
Tel: 978-322-4226
Fax: 978-322-4100


----------------------------------------------------------------
Please see the official ORACLE-L FAQ: http://www.orafaq.com
----------------------------------------------------------------
To unsubscribe send email to:  oracle-l-request_at_freelists.org
put 'unsubscribe' in the subject line.
--
Archives are at http://www.freelists.org/archives/oracle-l/
FAQ is at http://www.freelists.org/help/fom-serve/cache/1.html
-----------------------------------------------------------------