1. 程式人生 > >DML:insert ,update,delete

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