u014509493的博客

select * from all_tables a where --a.TABLE_NAME = ‘DEPT’;a.OWNER = ‘TIANSONG’;CREATE TABLE DEPT_BACK AS SELECT * FROM DEPT A ;SELECT * FROM DEPT_BACK A ;SELECT * FROM NEW_DEPT_BACK ;DROP TABLE DE...

oracle给已有数据的表增加自增主键：–给已有数据的表增加主键，并且自增：–1、先右键表编辑，增加一个id字段，可以为空。select * from emp;–2、给id字段设置值：update emp a set a.id = rownum ;commit;–3、新建一个序列：select count(1) from emp; --14 总数14，那么就让序列从14开始cr...

– Create tablecreate table ZB(zbnum varchar2(15),ZBBM VARCHAR2(500) not null,ZBFL VARCHAR2(50) not null,ZBMC VARCHAR2(100),ZBZS VARCHAR2(500),ZBGS VARCHAR2(500))select * from zb for update;...

–1、使用率、空闲率。select a.tablespace_name, round(a.total_size) “total_size(MB)”,round(a.total_size)-round(b.free_size,3) “used_size(MB)”,round(b.free_size,3) “free_size(MB)”, round(b.free_size/total_size...

–select * from emp;declare–i integer; --定义变量empno_num integer;begin–i := 1;empno_num := 9999;loop/* 插入数据 */insert into emp(EMPNO, ENAME, JOB, MGR, HIREDATE, SAL, COMM, DEPTNO)values(empno_...

–oracle分页查询sql语句select a.empno, a.ename, a.job, a.mgr, a.hiredate, a.sal, a.comm, a.deptno from emp a where a.ename = 'SMITH' ;–1、无ORDER BY排序的写法。(效率最高)SELECT * FROM (SE...