sql - 需要打印基于 IF 和 ELSE 限制的语句

Question

1. 如果订单的 SUM > 100 且 < 200 我需要将价格降低 10%

2. 如果订单的 SUM > 200 我需要将价格降低 20%

   BEGIN
   FOR item IN(SELECT ORDER_LINE.O_ID,SUM(INVENTORY.INV_PRICE) AS SUM,
   SUM(INVENTORY.INV_PRICE) -SUM(INVENTORY.INV_PRICE)*.10 AS TEN,
   SUM(INVENTORY.INV_PRICE) -SUM(INVENTORY.INV_PRICE)*.20 AS TWENTY
   FROM INVENTORY
   INNER JOIN ORDER_LINE
   ON INVENTORY.INV_ID = ORDER_LINE.INV_ID
   INNER JOIN ITEM
   ON ITEM.ITEM_ID = INVENTORY.ITEM_ID
   GROUP BY ORDER_LINE.O_ID
   ORDER BY ORDER_LINE.O_ID)
   IF item.SUM > 100 AND item.SUM < 200 THEN
   LOOP
   DBMS_OUTPUT.PUT_LINE(
   item.O_ID||' '||item.TEN);
   END LOOP;
   ELSE IF item.SUM > 200 THEN
   LOOP
   DBMS_OUTPUT.PUT_LINE(
   item.O_ID||' '||item.TWENTY);
   END LOOP;
   END IF;
   END;
   

Answer 1

您可以在您的 sql 中执行此操作：

SELECT 
  ORDER_LINE.O_ID,
  CASE WHEN 
    SUM(INVENTORY.INV_PRICE) > 100 AND SUM(INVENTORY.INV_PRICE) < 200 
  THEN
    SUM(INVENTORY.INV_PRICE)*0.9
  WHEN SUM(INVENTORY.INV_PRICE) > 200 THEN
    SUM(INVENTORY.INV_PRICE)*0.8
  ELSE
    SUM(INVENTORY.INV_PRICE)
  END SUM
FROM INVENTORY
INNER JOIN ORDER_LINE
ON INVENTORY.INV_ID = ORDER_LINE.INV_ID
INNER JOIN ITEM
ON ITEM.ITEM_ID = INVENTORY.ITEM_ID
GROUP BY ORDER_LINE.O_ID
ORDER BY ORDER_LINE.O_ID

请注意，当 sum=200 时，您的样本中没有折扣。
我建议您需要检查 sum >= 200 。