Oracle增加一列.修改一列数据类型: 添加一列: alter table A add( CFYJSNR varchar2(20)); 修改列: alter table A rename column CFYJSNR to CFJYSNR; 修改列的类型: alter table A modify cfyj varchar(200); 删除数据库一列 alter table A drop column CFYJSNR 使用心得,当使用plsql执行的时候,注意
1. 查看所有表空间大小 select tablespace_name,sum(bytes)/1024/1024 from dba_data_files group by tablespace_name; 2. 未使用的表空间大小 select tablespace_name,sum(bytes)/1024/1024 from dba_free_space group by tablespace_name; 3. 所以使用空间可以这样计算 select a.tablespace_name,tot
分别对T_USER表 进行增加name字段, 修改name字段,删除name字段 /*增加列表*/ ALTER TABLE T_USERS ADD name varchar2(512) ; /*删除列 */ ALTER TABLE T_USERS Drop column name ; /*修改列*/ ALTER TABLE T_USERS Modify name varchar2(512);
select tablespace_name, sum(bytes)/1024/1024 from dba_data_files group by tablespace_name; select tablespace_name, sum(bytes)/1024/1024 from dba_free_space group by tablespace_name; select * from dba_data_files t where t.tablespace_name = 'USERS' /ho
在SharePoint2007的错误日志中发现大量如下错误: 07/02/2013 16:17:25.99 OWSTIMER.EXE (0x0958) 0x097C Windows SharePoint Services Timer 5uuf Monitorable The previous instance of the timer job 'Application Server Timer Job', id '{0BAECAA4-B37F-4
--1.plsql中学习job --学习job --建表 create table test_job(para_date date); commit; insert into test_job values(sysdate); commit; select * from test_job; --建立存贮过程 create or replace procedure test_jobproce as begin insert into test_job values
33. 查询成绩比该课程平均成绩低的同学的成绩表. select * from score a where a.degree between 0 and( select avg(degree) from score b where a.cno=b.cno ) 34. 查询所有任课教师的Tname和Depart. select tname,depart from teacher where tno in( select tno from course ) 35 . 查询所有未讲课的教师的Tna
29.查询选修编号为"3-105"课程且成绩至少高于选修编号为"3-245"的同学的Cno.Sno和Degree,并按Degree从高到低次序排序. select tname,prof from teacher where depart = '计算机系' and prof not in ( select prof from teacher where depart = '电子工程系') 30.查询选修编号为"3-105"且成绩高于选修编号为&q
23.查询"张旭"教师任课的学生成绩. select * from score s where cno in ( select cno from course where tno in( select tno from teacher where tname = '张旭')) 24.查询选修某课程的同学人数多于5人的教师姓名. select tname from teacher where tno in ( select tno from course where cno in ( s