如何在postgresql 9.6中将json数组作为函数参数传递

Question

--Takes a json array to parse each elements as text .But it shows an error. --Change the type from json[] to json but not helps.

CREATE OR REPLACE FUNCTION public.test(in_param json[])
RETURNS integer
LANGUAGE 'plpgsql'
COST 100
VOLATILE 
AS $BODY$
declare 
 item text;
 arr1 text[];
 begin 
   for item in select * from json_array_elements_text(in_param ) loop
   arr1 = arr1||item;
   end loop;
return 0;
end;
$BODY$;
ALTER FUNCTION public.test(json[])
OWNER TO postgres;

Answer 1

I think you're mistaken. ["a","b","c"] cannot be cast to json[]. Appending square brackets ([]) creates a Postgres array datatype and is not self castable to a JSON array type

You'll receive this if you did so.

ERROR: malformed array literal

Rather, define your function to accept a simple JSON type

create or replace function test(json_in json) ..
..

Now, simply quoting your sample argument ["a","b","c"] will work

select  test('["a","b","c"]')

Demo