DML:insert ,update,delete
(1)insert: insert into tablename[(columnname,,,)] values(value1,,,); dept(deptno,dname,loc) dept(12,'abc','beijing') insert into dept(deptno,dname,loc) values(11,'abc','beijing'); insert into dept values(11,'abc','beijing');
insert into dept(dname,loc,deptno) values('abc','beijing',11);
dept(13,'jinan') insert into dept(deptno,loc) values(13,'jinan');
dept('qingdao') insert into dept(loc) values('qingdao'); 錯誤
方法二: insert into tablename[(columnname,,,)] select;
insert into dept(deptno,loc) select 13,'jinan' from dual union select 14,'linyi' from dual;
14,'linyi' 15,'zibo'
建立一個與表emp結構完全相同的表emp1,再把emp表的前3條記錄存入emp1中。
create table emp1 as select * from emp where 1=2; insert into emp1 select * from emp where rownum<4;
(2) update : update tablename set columnname=newvalue[,,, where];
給所有員工工資提升10% update emp set sal=sal*1.1;
給20號部門所有員工工資提升10% update emp set sal=sal*1.1 where deptno=20;
(3) delete : delete from tablename [where];
delete from emp; delete from emp where deptno=20;
(4) 事務: DML需要一個確認操作才能完成一個完整的事務。commit,rollback