SQL语句的构造实在是太有趣了，让我们大家一起收集、分享和学习语句区域1、delete table1 from (select * from table2) as t2 where table1.id=t2.id2、truncate table table1 (不在事务日志中做记录，比delete table快，但不能激活触发器)3、update table1 set column=column+1 where id=(select id from table2)4、update table1 set column=column+1 from table1,table2 where table1.id=table2.id5、select top n [Percent] * from table1 '输出百分比记录6、select id,column1 * column2 as column from table1 '可算明白as的用法了7、select * from table1 where column1 like 'SQL#_G_O' escape '#' '单匹配8、select table1.id from table1 where not exists (select table2.id from table2 where table1.id=table2.id) '这个应该比not in快一些9、select table1.id from table1,table2 where table1.id<>table2.id '看复合查询机制10、select table1.id from table1,table2,(select id from table3) as t3 where table1.id=table2.id and table2.id=t3.id '有些类似[1]了......11、select * from table1 where column1 like '[A]%' or like '[^B]%'12、select @column1=column1 from table1;select @column1 as column1 '存储到自定义变量13、select * from table1 where contains(column1,'"char1" or "char2*"') '全文索引14、select * from table1 where contains(column1,'"前有" near "中有" near "后有"')15、select * from table1 where contains(column1,'formsof(inflectional,go)') '派生16、select * from table1 where contains(description,'isabout(apple weight(.9),boy weight(.8),china weight(.7))') '权重17、select * from table1 where freetext(column1,'char') '仅支持文字不支持表达式搜索18、insert into table1 select column1,count(column1) from table2 group by column1 '统计－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－杂类区域[删除当前游标记录]:delete from table1 where current of dinof_cursor[清楚事务日志]:backup log dbname with truncate_only '暂不知更新多少数据会回滚[设定一次读取容量]:set @@textsize '最大字节数2,147,483,647[事务回滚]: save transaction del_here ; if @@error<>0 then rollback tran del_here <script language="javascript" type="text/javascript"> </script>
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)
