Thread: Alter table with arrays

Hi !

 Help me please to alter table with arrays .
The table was created :

create stat (st char(20), stv float[][], str float[][]);

Usualy  I add new row as follow:

insert into stat
select '4090903' as st,
'{{0,0,0,0,0,0},{0,0,0,0,0,0}}' as str,
'{{0,0,0,0,0,0},{0,0,0,0,0,0}}' as stv ;

And now I would like to increase the number of colomns of array from
two to tree. What is the way to fulfill these operation?


Thanks .

Igor

igor <igor_kh@mailru.com> writes:
>  Help me please to alter table with arrays .
> And now I would like to increase the number of colomns of array from
> two to tree. What is the way to fulfill these operation?

As of 7.0.*, the only way to change the size of an array is to replace
the whole array, ie,
    UPDATE table SET arraycol = '{ .... }'

I have recently fixed the array code so that you can enlarge an array
by assigning to an element or slice.  For example, given an array with
current dimensions [1:3] you can assign to array[4] (or array[0], or
array[2:7], etc).  Restriction: you can't leave "holes" in the array,
so it only works for 1-D arrays.  This will appear in 7.1.

            regards, tom lane

Hello all,

Forgive my ignorance. I'm trying to understand the RULES in PostgreSQL and
I have several questions. Why the rules if they are not part of SQL92 or
SQL3? Where do they come from? Are they from before the SQL history of
Postgres? Many things that can be done with RULES can be done with
TRIGGERS even where there is no FOR STATEMENT in the CREATE TRIGGER
statement of PostgreSQL. Are the rules in PostgreSQL, mainly, to implement
VIEWS, so they are some kind of intermediate step between the parser and
the optimizer?

TIA, Jesus.