RETURN QUERY EXECUTE 'some dynamic query'

RETURN QUERY EXECUTE 'some dynamic query'

GET DIAGNOSTICS variable = ROW_COUNT;
IF variable < 10 THEN

    # I don't know what to do here or how to accomplish this

END IF;

EXECUTE 'dynamic query';

GET DIAGNOSTICS variable = ROW_COUNT;
IF variable >= 10 THEN
    RETURN QUERY EXECUTE 'dynamic query';
END IF;

test=> CREATE OR REPLACE FUNCTION temptabl(cnt integer)
RETURNS SETOF integer AS
$body$
BEGIN
    CREATE TEMPORARY TABLE tmp_container ON COMMIT DROP AS
    SELECT a
    FROM generate_series(1, cnt) t(a);

    IF (SELECT count(1) FROM tmp_container) > 5
    THEN
        RETURN QUERY SELECT a FROM tmp_container;
    END IF;
END;
$body$
LANGUAGE plpgsql;


test=> SELECT * FROM temptabl(4);
 temptabl
----------
(0 rows)

test=> SELECT * FROM temptabl(6);
 temptabl
----------
        1
        2
        3
        4
        5
        6
(6 rows)

CREATE OR REPLACE FUNCTION f_min_records(min_ct integer = 10)  -- default minimum 10
  RETURNS SETOF tbl AS
$func$
DECLARE
   row_ct int;
BEGIN
   RETURN QUERY EXECUTE 'some dynamic query (matching return type)';

   GET DIAGNOSTICS row_ct = ROW_COUNT;

   IF row_ct < min_ct THEN
      RAISE EXCEPTION 'Only % rows! Requested minimum was %.', row_ct, min_ct;
   END IF;
END
$func$  LANGUAGE plpgsql;

SELECT * FROM f_min_records_wrapper();

CREATE OR REPLACE FUNCTION f_min_records(min_ct integer = 10)  -- default minimum 10
  RETURNS SETOF t AS
$func$
DECLARE
   row_ct int;
BEGIN
   RETURN QUERY EXECUTE 'SELECT * from t';   -- some dynamic query (matching return type)

   GET DIAGNOSTICS row_ct = ROW_COUNT;

   IF row_ct < min_ct THEN
      RAISE SQLSTATE 'BRRRR'   -- 5 ASCII chars
      USING MESSAGE = format('Only %s rows! Requested minimum was %s.', row_ct, min_ct);
   END IF;

END
$func$  LANGUAGE plpgsql;

CREATE OR REPLACE FUNCTION f_min_records_wrapper(min_ct integer = 10)
  RETURNS SETOF t AS
$func$
BEGIN
   RETURN QUERY
   SELECT * from f_min_records(min_ct);

EXCEPTION
   WHEN SQLSTATE 'BRRRR' THEN
   RAISE NOTICE '%', SQLERRM;  -- optionally pass error msg
END
$func$  LANGUAGE plpgsql;

SELECT * FROM f_min_records_wrapper(17);

CREATE OR REPLACE FUNCTION f_temptbl(min_ct integer = 10)
  RETURNS SETOF t AS
$func$
DECLARE
   row_ct int;
BEGIN
   DROP TABLE IF EXISTS _temptbl;                      -- for mult. calls in 1 transaction
   CREATE TEMP TABLE _temptbl (LIKE t) ON COMMIT DROP; -- match RETURNS type

   EXECUTE 'INSERT INTO _temptbl SELECT * FROM t';     -- text with dyn SQL

   GET DIAGNOSTICS row_ct = ROW_COUNT;

   IF row_ct >= min_ct THEN
      RETURN QUERY TABLE _temptbl;
   END IF;
END;
$func$  LANGUAGE plpgsql;

RETURN CANCEL;

RETURN CANCEL 10;