NOTICE:  table "temp_table" does not exist, skipping

ERROR:  could not open file "/Users/linu/downloads/numb.csv" for reading: No such file or directory
HINT:  COPY FROM instructs the PostgreSQL server process to read a file. You may want a client-side facility such as psql's copy.
CONTEXT:  SQL statement "copy temp_table from '/Users/linu/downloads/numb.csv' with delimiter ';' quote '"' csv "
PL/pgSQL function staging.load_csv_file(text,text,integer) line 22 at EXECUTE
SQL state: 58P01

**Function call**
select staging.load_csv_file('dhl','/Users/linu/downloads/numb.csv',73)

**Function Body**
create or replace function staging.load_csv_file
(
    target_table text,
    csv_path text,
    col_count integer
)

returns void as $$

declare

iter integer; -- dummy integer to iterate columns with
col text; -- variable to keep the column name at each iteration
col_first text; -- first column name, e.g., top left corner on a csv file or spreadsheet

begin
    set schema 'staging';

    DROP TABLE IF EXISTS temp_table;
    create  table temp_table ();

    -- add just enough number of columns
    for iter in 1..col_count
    loop
        execute format('alter table temp_table add column col_%s text;', iter);
    end loop;

    -- copy the data from csv file
    execute format('copy temp_table from %L with delimiter '';'' quote ''"'' csv ', csv_path);

    iter := 1;
    col_first := (select col_1 from temp_table limit 1);
  -- raise notice 'path', csv_path;
    -- update the column names based on the first row which has the column names
    for col in execute format('select unnest(string_to_array(trim(temp_table::text, ''()''), '','')) from temp_table where col_1 = %L', col_first)
    loop
        execute format('alter table temp_table rename column col_%s to %s', iter, col);
        iter := iter + 1;
    end loop;

    -- delete the columns row
    execute format('delete from temp_table where %s = %L', col_first, col_first);

    -- change the temp table name to the name given as parameter, if not blank
    if length(target_table) > 0 then
        execute format('alter table temp_table rename to %I', target_table);
    end if;

end;

$$ language plpgsql;