Oracle常用语句记录

交集/差集/合集
	select * from tb_a
		intersect
		minus
		union all
	select * from tb_b

条件分支 decode()
	例如：搜索条件没有手机就查座机 默认查手机
	SELECT * FROM
	AND DECODE(SEND_MOBILE,NULL,TELNUM,SEND_MOBILE) LIKE '110'

行号输出
	row_number() OVER(ORDER BY null)
	或者 rownum伪列

聚合输出
	SELECT LISTAGG(STUNAME,'+') WITHIN GROUP (ORDER BY STUNUM) OVER (PARTITION BY CLASSNAME)
	FROM STU_INFO

同时进行INSERT+UPDATE 即：如果某数据已存在于表1中则UPDATE表1，否则INSERT
	MERGE INTO TBL1 T1
	USING (SELECT 'D0001' ID,'KING' NAME FROM DUAL) T2
	ON (T1.ID = T2.ID)
	WHEN MATCHED THEN
	  UPDATE SET NAME = T2.NAME
	WHEN NOT MATCHED THEN
	  INSERT VALUES(T2.ID,T2.NAME)

与上一条数据一并输出
	SELECT '轮到'||STU_NAME,'下一个是'||LAG(STU_NAME,1) IGNORE NULLS OVER(ORDER BY STUNUM) FROM STUINFO