说明:复制表(只复制结构,源表名:a 新表名:b)

SQL: select * into b from a where 1<>1

说明:拷贝表(拷贝数据,源表名:a 目标表名:b)

SQL: insert into b(a, b, c) select d,e,f from b;

说明:显示文章、提交人和最后回复时间

SQL: select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b

说明:外连接查询(表名1:a 表名2:b)

SQL: select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c

说明:日程安排提前五分钟提醒

SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5

说明:两张关联表,删除主表中已经在副表中没有的信息

SQL:

delete from info where not exists ( select * from infobz where info.infid=infobz.infid )

说明:–

SQL:

SELECT A.NUM, A.NAME, B.UPD_DATE, B.PREV_UPD_DATE  
FROM TABLE1,  
 (SELECT X.NUM, X.UPD_DATE, Y.UPD_DATE PREV_UPD_DATE   
 FROM (SELECT NUM, UPD_DATE, INBOUND_QTY, STOCK_ONHAND   
 FROM TABLE2   
 WHERE TO_CHAR(UPD_DATE,'YYYY/MM') = TO_CHAR(SYSDATE, 'YYYY/MM')) X,   
 (SELECT NUM, UPD_DATE, STOCK_ONHAND   
 FROM TABLE2   
 WHERE TO_CHAR(UPD_DATE,'YYYY/MM') =   
 TO_CHAR(TO_DATE(TO_CHAR(SYSDATE, 'YYYY/MM') ¦¦ '/01','YYYY/MM/DD') – 1, 'YYYY/MM') ) Y,   
 WHERE X.NUM = Y.NUM (+)   
 AND X.INBOUND_QTY + NVL(Y.STOCK_ONHAND,0) X.STOCK_ONHAND ) B   
WHERE A.NUM = B.NUM  

说明:–

SQL:

select * from studentinfo where not exists(select * from student where studentinfo.id=student.id) and 系名称='”&strdepartmentname&”' and 专业名称='”&strprofessionname&”' order by 性别,生源地,高考总成绩  

说明:

从数据库中去一年的各单位电话费统计(电话费定额贺电化肥清单两个表来源)

SQL:

SELECT a.userper, a.tel, a.standfee, TO_CHAR(a.telfeedate, 'yyyy') AS telyear,  
 SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '01', a.factration)) AS JAN,   
 SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '02', a.factration)) AS FRI,   
 SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '03', a.factration)) AS MAR,   
 SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '04', a.factration)) AS APR,   
 SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '05', a.factration)) AS MAY,   
 SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '06', a.factration)) AS JUE,   
 SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '07', a.factration)) AS JUL,   
 SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '08', a.factration)) AS AGU,   
 SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '09', a.factration)) AS SEP,   
 SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '10', a.factration)) AS OCT,   
 SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '11', a.factration)) AS NOV,   
 SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '12', a.factration)) AS DEC   
FROM (SELECT a.userper, a.tel, a.standfee, b.telfeedate, b.factration  
 FROM TELFEESTAND a, TELFEE b   
 WHERE a.tel = b.telfax) a   
GROUP BY a.userper, a.tel, a.standfee, TO_CHAR(a.telfeedate, 'yyyy')  

说明:四表联查问题:

SQL:

select * from a left inner join b on a.a=b.b right inner join c on a.a=c.c inner join d on a.a=d.d where …..  

说明:得到表中最小的未使用的ID号

SQL:

SELECT (CASE WHEN EXISTS(SELECT * FROM Handle b WHERE b.HandleID = 1) THEN MIN(HandleID) + 1 ELSE 1 END) as HandleID  
FROM Handle  
WHERE NOT HandleID IN (SELECT a.HandleID – 1 FROM Handle a)  

相同的记录:

select * from a join b on a.id=b.id  

删除相同的记录:

delete a from b ,a where a.id=b.id;  

不同的记录

select * from a where a.id not in(select id from b)  
union  
select * from b where b.id not in(select id from a)  

查找某段时间内的用户资料

select * from dbms_user_info_def t where crbt_Status='N' and to_char(reg_date,'yyyy-mm-dd hh24:mm:ss') between '2005-01-01 00:00:00' and '2005-01-26 00:00:00';  

合并表

insert into a select * from b;