case when 的实战应用

SELECT
lg.product_id,
lg.goods_id,
lg.goods_no,
lg.product_price,
lg.product_stock,
lg.limit_amount,
lg.is_delivery_free,
lg.limit_order,
lg.state,
gs.MARKET_PRICE,
lg.standby1 AS kan_product_stock,
sg.goods_name,
<![CDATA[
(CASE
   WHEN lg.LIMIT_GOODS_IMG IS NOT NULL
      THEN lg.LIMIT_GOODS_IMG
    ELSE sg.goods_list_img
END
) AS goods_list_img,
 ]]>
sg.goods_price,
lg.cu_title
FROM
T_LIMIT_GOODS lg,
shop_common_goods sg,
(
SELECT
gg.market_price,
gg.goods_id
FROM
product pp,
goods gg
WHERE
gg.PRODUCT_ID = pp.product_id
AND pp.is_onsale = ‘Y‘
AND pp.is_delete = ‘N‘
AND gg.is_delete = ‘N‘
) gs
WHERE
lg.goods_id = sg.goods_id(+)
AND lg.goods_id = gs.goods_id
AND lg.is_delete = ‘N‘
AND sg.is_delete = ‘N‘
AND lg.state = ‘enable‘
AND <!

[CDATA[ to_date(lg.limit_begin_time, ‘YYYY/MM/DD hh24:mi:ss‘)<=to_date(#{limitEndTime}, ‘YYYY/MM/DD hh24:mi:ss‘)]]>
AND sg.goods_type = #{goodsType}
AND lg.field_id = #{fieldId}
ORDER BY lg.LIMIT_ORDER