array_append function is not working

问题

I need to append an item to existed array in postgresql. I wrote this code (plpgsql function):

perform array_append (arrayA::integer[],id);

Since it didn't work I tried:

raise notice '%', arrayA;
perform array_append (arrayA::integer[],id);
raise notice '%', arrayA;

It gives:

NOTICE:  <NULL>
NOTICE:  <NULL>

Why the array isn't updated?

回答1:

PERFORM query discard the results. array_append doesn't update the array you specify in the first parameter. It only reads the its values.

You should change your code to:

select array_append (arrayA::integer[],id) into v_arrayA;

来源：https://stackoverflow.com/questions/34337175/array-append-function-is-not-working