This section explains the flow of DBMS_SQL and provides an example.

CREATE FUNCTION smp_00()
RETURNS INTEGER
AS $$
DECLARE
    str_sql     VARCHAR(255);
    cursor      INTEGER;
    h_smpid     INTEGER;
    v_smpid     INTEGER;
    v_smpnm     VARCHAR(20);
    v_smpage    INTEGER;
    errcd       INTEGER;
    length      INTEGER;
    ret         INTEGER;
BEGIN
    str_sql     := 'SELECT smpid, smpnm, smpage FROM smp_tbl WHERE smpid < :H_SMPID ORDER BY smpid';
    h_smpid     := 3;
    v_smpid     := 0;
    v_smpnm     := '';
    v_smpage    := 0;

    cursor := DBMS_SQL.OPEN_CURSOR();

    PERFORM DBMS_SQL.PARSE(cursor, str_sql, 1);

    PERFORM DBMS_SQL.BIND_VARIABLE(cursor, ':H_SMPID', h_smpid);

    PERFORM DBMS_SQL.DEFINE_COLUMN(cursor, 1, v_smpid);
    PERFORM DBMS_SQL.DEFINE_COLUMN(cursor, 2, v_smpnm, 10);
    PERFORM DBMS_SQL.DEFINE_COLUMN(cursor, 3, v_smpage);

    ret := DBMS_SQL.EXECUTE(cursor);
    loop
        if DBMS_SQL.FETCH_ROWS(cursor) = 0 then
            EXIT;
        end if;

        SELECT value,column_error,actual_length INTO v_smpid,errcd,length FROM DBMS_SQL.COLUMN_VALUE(cursor, 1, v_smpid);
        RAISE NOTICE '--------------------------------------------------------';
        RAISE NOTICE '--------------------------------------------------------';
        RAISE NOTICE 'smpid       = %', v_smpid;
        RAISE NOTICE 'errcd       = %', errcd;
        RAISE NOTICE 'length      = %', length;

        SELECT value,column_error,actual_length INTO v_smpnm,errcd,length FROM DBMS_SQL.COLUMN_VALUE(cursor, 2, v_smpnm);
        RAISE NOTICE '--------------------------------------------------------';
        RAISE NOTICE 'smpnm       = %', v_smpnm;
        RAISE NOTICE 'errcd       = %', errcd;
        RAISE NOTICE 'length      = %', length;

        select value,column_error,actual_length INTO v_smpage,errcd,length FROM DBMS_SQL.COLUMN_VALUE(cursor, 3, v_smpage);
        RAISE NOTICE '--------------------------------------------------------';
        RAISE NOTICE 'smpage      = %', v_smpage;
        RAISE NOTICE 'errcd       = %', errcd;
        RAISE NOTICE 'length      = %', length;
        RAISE NOTICE '';
    end loop;

    cursor := DBMS_SQL.CLOSE_CURSOR(cursor);
    RETURN 0;
END;
$$ LANGUAGE plpgsql;