segment查詢，方便建立索引

DECLARE
v_SegNum VARCHAR2(9);
v_FreqCount NUMBER;
BEGIN
FOR i IN 1..30
LOOP
EXECUTE IMMEDIATE ‘SELECT COUNT(DISTINCT SEGMENT’||TO_CHAR(i)||’) FROM gl_code_combinations’ INTO v_FreqCount ;
IF v_freqCount <> 0 THEN
DBMS_OUTPUT.PUT_LINE( ‘SEGMENT’||TO_CHAR(i)||’ Frequency = ‘||TO_CHAR(v_FreqCount));
END IF;
END LOOP;
END;