Firebird's execute statement with bigint named input parameter

Question

Let's say I have a code like this:

execute block
as
declare var_mask bigint;
declare var_dummy int;
begin
    var_mask = bin_shl(1, (64 - 1));

    execute statement ('
select first 1 null
from rdb$database
where bin_and(cast(0 as bigint), :var_mask) <> cast(0 as bigint)
    ')
    (var_mask := var_mask)
    into :var_dummy
    ;
end

This one gives nice arithmetic exception, numeric overflow, or string truncation. numeric value is out of range..

To make it work I have to do explicit cast of the variable:

execute block
as
declare var_mask bigint;
declare var_dummy int;
begin
    var_mask = bin_shl(1, (64 - 1));

    execute statement ('
select first 1 null
from rdb$database
where bin_and(cast(0 as bigint), cast(:var_mask as bigint)) <> cast(0 as bigint)
    ')
    (var_mask := var_mask)
    into :var_dummy
    ;
end

Does anybody know why? The type information should carry, isn't it?

Answer 1

To add to Adriano's answer the type information actually does not carry - more here, from me actually :).

Answer 2

Because BIN_AND describes the second parameter as INTEGER, even when you pass a BIGINT to the first one. Whether this is good or bad is subject to discussion.