select CASE when filelength is null then '0' else filelength end filelength from bs13.t_mediasource where filelength is null
2)oracle的if else then
select nvl(wg38,0) from bs13.jngl
3)oracle的decode
select wg35, decode(nvl(wg38,'0'),'0','优秀','orther') from bs13.jngl select id, decode(sign(score-85),1,'优秀',0,'优秀',-1, decode(sign(score-70),1,'良好',0,'良好',-1, decode(sign(score-60),1,'及格',0,'及格',-1,'不及格'))) from student select sid,serial#,username, DECODE(command, 0,'None', 2,'Insert', 3,'Select', 6,'Update', 7,'Delete', 8,'Drop', 'Other') cmmand from v$session where username is not null;
3)oracle的case when where 用法
SELECT T2.*, T1.* FROM T1, T2 WHERE (CASE WHEN T2.COMPARE_TYPE = 'A' AND T1.SOME_TYPE LIKE 'NOTHING%' THEN 1 WHEN T2.COMPARE_TYPE != 'A' AND T1.SOME_TYPE NOT LIKE 'NOTHING%' THEN 1 ELSE 0 END) = 1
set define off; Select 'Tom&Jerry' from dual; Select 'Tom'||'&'||'Jerry' from dual;