Re: how to prepare a create table statement

po 4. 1. 2021 v 11:31 odesílatel Alexander Mills <
alexander(dot)d(dot)mills(at)gmail(dot)com> napsal:

> I am trying to create 500 partitions using a loop:
>
> do $$
> declare
> counter integer := 0;
> begin
> while counter <= 500 loop
> PREPARE create_table(int) AS
> CREATE TABLE mbk_auth_method_$1 PARTITION OF mbk_auth_method FOR VALUES WITH (modulus 500, remainder $1);
> EXECUTE create_table (counter);
> counter := counter + 1;
> end loop;
> end$$;
>
>
> problem is that a CREATE TABLE cannot be prepared statement..
>
> Anyone know how I can accomplish the above? Seems like this is a missing
> feature - to prepare a CREATE TABLE statement..
>

This is a bad idea. You should not use PREPARE statement in plpgsql code
ever. Your code looks like from MySQL :)

do $$
begin
for i in 0..500
loop
execute format('CREATE TABLE %I PARTITION OF mbk_auth_method FOR VALUES
WITH (modulus 500, remainder %s)',
'mbk_auth_method_' || i, i);
end loop;
end;
$$;

It can be a little bit messy, but EXECUTE from the plpgsql environment is a
different statement than EXECUTE from SQL environment. Dynamic statements
are "prepared" implicitly in plpgsql. You cannot use PREPARE there.

Regards

Pavel