oracle函數學習記錄

decode：

SELECT

available,

decode(available,0,'失效',1,'有效')

from TABLE;

PS:如果available=0，傳回‘失效’

||：select id||'_1' id from table

ps:傳回的結果為id_1

nvl  通過查詢擷取某個字段的合計值，如果為空，則賦與一個預設值

SELECT

NVL (MAX(ORDER_NUM), 0) + 1 AS MAXORDERNUM

FROM

AMS_APP_POINTS_INFO