Thread: ALTER Table

ALTER Table

From

Alex

Date:

31 October 2003, 10:04:50

Hi,
is it possible to add a column to a table at a specific place ? Reading
the man pages i could not figure that out.

Thanks.
Alex

Re: ALTER Table

From

Shridhar Daithankar

Date:

31 October 2003, 10:16:43

Alex wrote:
> is it possible to add a column to a table at a specific place ? Reading
> the man pages i could not figure that out.

Why do you want to add it at specific location? What does it achieve?

  Shridhar

Re: ALTER Table

From

Gaetano Mendola

Date:

31 October 2003, 11:24:22

Shridhar Daithankar wrote:

> Alex wrote:
>
>> is it possible to add a column to a table at a specific place ?
>> Reading the man pages i could not figure that out.
>
>
> Why do you want to add it at specific location? What does it achieve?

I miss the same feature too, this is my reason:
is just to keep clean your schema, I have in my revision control system
all tables with fields grouped for tipology:

CREATE TABLE a(

   G1  as INTEGER,
   ...
   Gn  as INTEGER,
   H1  as INTEGER,
   ...
   Hm  as INTEGER
);

when I add let me say Gn+1 in my RCS I have:

CREATE TABLE a(

   G1   as INTEGER,
   ...
   Gn   as INTEGER,
   Gn+1 as INTEGER,
   H1   as INTEGER,
   ...
   Hm   as INTEGER
);

and will be nice to have in my fourther dumps
the same structure, just to do a DIFF betwen two schemas
without become crazy!


I hope I was clear enough.


Regards
Gaetano Mendola

Re: ALTER Table

From

Shridhar Daithankar

Date:

31 October 2003, 11:58:25

Gaetano Mendola wrote:

> Shridhar Daithankar wrote:
>
>> Alex wrote:
>>
>>> is it possible to add a column to a table at a specific place ?
>>> Reading the man pages i could not figure that out.
>>
>>
>>
>> Why do you want to add it at specific location? What does it achieve?
>
>
> I miss the same feature too, this is my reason:
> is just to keep clean your schema, I have in my revision control system
> all tables with fields grouped for tipology:
>
> CREATE TABLE a(
>
>   G1  as INTEGER,
>   ...
>   Gn  as INTEGER,
>   H1  as INTEGER,
>   ...
>   Hm  as INTEGER
> );
>
> when I add let me say Gn+1 in my RCS I have:
>
> CREATE TABLE a(
>
>   G1   as INTEGER,
>   ...
>   Gn   as INTEGER,
>   Gn+1 as INTEGER,
>   H1   as INTEGER,
>   ...
>   Hm   as INTEGER
> );
>
> and will be nice to have in my fourther dumps
> the same structure, just to do a DIFF betwen two schemas
> without become crazy!

Well, if you diff two schema dumps, you will find one line added to correct
scope i.e. {} block because it belongs to same table. And anyway there is big
difference between schema diffs and database diffs. Sure you can not produce an
SQL script which would bring two databases to same state.

Only thing that can be done is to manually reordering the schema since it gives
you pretty localised view of changes due to repository.

Also check http://www.varlena.com/varlena/GeneralBits/30.html. The last bit
summerises another discussion on this.

HTH

  Shridhar

Re: ALTER Table

From

Gaetano Mendola

Date:

31 October 2003, 13:11:03

Shridhar Daithankar wrote:

> Gaetano Mendola wrote:
>
>> Shridhar Daithankar wrote:
>>
>>> Alex wrote:
>>>
>>>> is it possible to add a column to a table at a specific place ?
>>>> Reading the man pages i could not figure that out.
>>>
>>>
>>>
>>>
>>> Why do you want to add it at specific location? What does it achieve?
>>
>>
>>
>> I miss the same feature too, this is my reason:
>> is just to keep clean your schema, I have in my revision control system
>> all tables with fields grouped for tipology:
>>
>> CREATE TABLE a(
>>
>>   G1  as INTEGER,
>>   ...
>>   Gn  as INTEGER,
>>   H1  as INTEGER,
>>   ...
>>   Hm  as INTEGER
>> );
>>
>> when I add let me say Gn+1 in my RCS I have:
>>
>> CREATE TABLE a(
>>
>>   G1   as INTEGER,
>>   ...
>>   Gn   as INTEGER,
>>   Gn+1 as INTEGER,
>>   H1   as INTEGER,
>>   ...
>>   Hm   as INTEGER
>> );
>>
>> and will be nice to have in my fourther dumps
>> the same structure, just to do a DIFF betwen two schemas
>> without become crazy!
>
>
> Well, if you diff two schema dumps, you will find one line added to
> correct scope i.e. {} block because it belongs to same table. And anyway
> there is big difference between schema diffs and database diffs. Sure
> you can not produce an SQL script which would bring two databases to
> same state.
>
> Only thing that can be done is to manually reordering the schema since
> it gives you pretty localised view of changes due to repository.
>
> Also check http://www.varlena.com/varlena/GeneralBits/30.html. The last
> bit summerises another discussion on this.

Yes but the missing feature is there.


Regards
Gaetano Mendola