oracle——笔记——DML 数据操作语句：insert 、update 、delete

￡神魔★判官ぃ 2023-10-02 08:14 12阅读 0赞

create table emp2 ( empno number(4),
                        ename varchar2(10),
                        job varchar2(9),
                        mgr number(4),
                        hiredate date,
                        sal number(7,2),
                        comm number(7,2),
                        deptno number(2) 
                     );
    -----------------------------------------------------------------------------------------------------------
    
    insert into emp2 (EMPNO, ENAME, JOB, MGR, HIREDATE, SAL, COMM, DEPTNO)
    values (7369, 'SMITH', 'CLERK', 7902, to_date('17-12-1980', 'dd-mm-yyyy'), 800.00, null, 20);
    
    insert into emp2 (EMPNO, ENAME, JOB, MGR, HIREDATE, SAL, COMM, DEPTNO)
    values (7499, 'ALLEN', 'SALESMAN', 7698, to_date('20-02-1981', 'dd-mm-yyyy'), 1600.00, 300.00, 30);
    
    insert into emp2 (EMPNO, ENAME, JOB, MGR, HIREDATE, SAL, COMM, DEPTNO)
    values (7521, 'WARD', 'SALESMAN', 7698, to_date('22-02-1981', 'dd-mm-yyyy'), 1250.00, 500.00, 30);
    
    insert into emp2 (EMPNO, ENAME, JOB, MGR, HIREDATE, SAL, COMM, DEPTNO)
    values (7566, 'JONES', 'MANAGER', 7839, to_date('02-04-1981', 'dd-mm-yyyy'), 2975.00, null, 20);
    
    insert into emp2 (EMPNO, ENAME, JOB, MGR, HIREDATE, SAL, COMM, DEPTNO)
    values (7654, 'MARTIN', 'SALESMAN', 7698, to_date('28-09-1981', 'dd-mm-yyyy'), 1250.00, 1400.00, 30);
    
    insert into emp2 (EMPNO, ENAME, JOB, MGR, HIREDATE, SAL, COMM, DEPTNO)
    values (7698, 'BLAKE', 'MANAGER', 7839, to_date('01-05-1981', 'dd-mm-yyyy'), 2850.00, null, 30);
    
    insert into emp2 (EMPNO, ENAME, JOB, MGR, HIREDATE, SAL, COMM, DEPTNO)
    values (7782, 'CLARK', 'MANAGER', 7839, to_date('09-06-1981', 'dd-mm-yyyy'), 2450.00, null, 10);
    
    insert into emp2 (EMPNO, ENAME, JOB, MGR, HIREDATE, SAL, COMM, DEPTNO)
    values (7788, 'SCOTT', 'ANALYST', 7566, to_date('19-04-1987', 'dd-mm-yyyy'), 3000.00, null, 20);
    
    insert into emp2 (EMPNO, ENAME, JOB, MGR, HIREDATE, SAL, COMM, DEPTNO)
    values (7839, 'KING', 'PRESIDENT', null, to_date('17-11-1981', 'dd-mm-yyyy'), 5000.00, null, 10);
    
    insert into emp2 (EMPNO, ENAME, JOB, MGR, HIREDATE, SAL, COMM, DEPTNO)
    values (7844, 'TURNER', 'SALESMAN', 7698, to_date('08-09-1981', 'dd-mm-yyyy'), 1500.00, 0.00, 30);
    
    insert into emp2 (EMPNO, ENAME, JOB, MGR, HIREDATE, SAL, COMM, DEPTNO)
    values (7876, 'ADAMS', 'CLERK', 7788, to_date('23-05-1987', 'dd-mm-yyyy'), 1100.00, null, 20);
    
    insert into emp2 (EMPNO, ENAME, JOB, MGR, HIREDATE, SAL, COMM, DEPTNO)
    values (7900, 'JAMES', 'CLERK', 7698, to_date('03-12-1981', 'dd-mm-yyyy'), 950.00, null, 30);
    
    insert into emp2 (EMPNO, ENAME, JOB, MGR, HIREDATE, SAL, COMM, DEPTNO)
    values (7902, 'FORD', 'ANALYST', 7566, to_date('03-12-1981', 'dd-mm-yyyy'), 3000.00, null, 20);
    
    insert into emp2 (EMPNO, ENAME, JOB, MGR, HIREDATE, SAL, COMM, DEPTNO)
    values (7934, 'MILLER', 'CLERK', 7782, to_date('23-01-1982', 'dd-mm-yyyy'), 1300.00, null, 10);
    
    =============================================================================================================================
    
    create table dept2 ( deptno number(2),
                         dname varchar2(14),
                         loc varchar2(13)
                       );
    
    ----------------------------------------------------
    
    insert into dept2 (DEPTNO, DNAME, LOC)
    values (10, 'ACCOUNTING', 'NEW YORK');
    
    insert into dept2 (DEPTNO, DNAME, LOC)
    values (20, 'RESEARCH', 'DALLAS');
    
    insert into dept2 (DEPTNO, DNAME, LOC)
    values (30, 'SALES', 'CHICAGO');
    
    insert into dept2 (DEPTNO, DNAME, LOC)
    values (40, 'OPERATIONS', 'BOSTON');
    
    ============================================================
    
    create table salgrade2 ( grade number,
                             losal number,
                             hisal number
                           );
    
    --------------------------------------------------
    
    insert into salgrade2 (GRADE, LOSAL, HISAL)
    values (1, 700, 1200);
    
    insert into salgrade2 (GRADE, LOSAL, HISAL)
    values (2, 1201, 1400);
    
    insert into salgrade2 (GRADE, LOSAL, HISAL)
    values (3, 1401, 2000);
    
    insert into salgrade2 (GRADE, LOSAL, HISAL)
    values (4, 2001, 3000);
    
    insert into salgrade2 (GRADE, LOSAL, HISAL)
    values (5, 3001, 9999);
    
    
    ========================================================
    
    select * from emp2;
    
    select * from dept2;
    
    select * from salgrade2;
    
    =====================================
    select * from emp2;        --employee2 员工表
    select * from dept2;       --department2 部门表
    select * from salgrade2;   -- salary grade2 工资等级表
    
    -----------------------------------------------------
    emp2
    
    empno    员工编号
    ename    员工姓名
    job      工作/工种
    mgr      manager上级编号
    hiredate 入职日期
    sal      salary 工资
    comm     奖金/津贴
    deptno   部门编号
    ---------------------
    
    dept2
    
    deptno  部门号
    dname   部门名称
    loc     所在地
    ---------------------------
    salgrade2
    
    grade                   等级
    losal lowest salary     最低工资
    hisal high salary       最高工资
    
    =============================================
    
    
     
    DML 数据操作语句：insert  update delete
    
    新增：insert into
    
       insert into 表名 values();
    
       insert into 表名(列) 子查询; 
    
       insert into emp94(eid,ename) select 1122,'abc' from dual
                                    union
                                    select 1123,'abd' from dual
                                    union
                                    select 1124,'acd' from dual; 
    
       create table emp94(eid integer,
                          ename varchar(10),
                          birth date,
                          classno number(2));
    
       select * from emp94;
    
       insert into emp94(eid,classno) values(1234,11);
       insert into emp94(eid,classno) select empno,deptno from emp;  
       
    
    
    
    
    
    
    
    更改： update
    
    
      update 表名 set 列名=值;
      update 表名 set 列名=值 where ……;
      update 表名 set 列1=值1,列2=值2,…… where ……;
      update 表名 set 列=子查询 where ……;
      update 表名 set 列1=子查询,列2=子查询,…… where ……;
     
      update emp2 set sal = 9000,deptno=40 where job = 'CLERK';
     
    把emp中，员工的工资翻倍 奖金在原奖金基础上+500 ：
    
      update emp2 set sal=sal*2,comm=nvl(comm,0)+500;
     
    把SMITH 的工资改成与KING 一样：
    
    update emp2 set sal = (select sal from emp2 where ename = 'KING')
    where ename = 'SMITH';
     
    把ALLEN 改成 与CLARK同部门：
    
    update emp set deptno = (select deptno from emp where ename='CLARK')
    where ename = 'ALLEN';
    
    把与BLAKE 同工作的员工的上级，改成SCOTT：
    
      update emp set mgr = SCOTT的empno
      where job = BLAKE的job;
      
    把处于平均工资以下的员工，都调到BOSTON (部门的loc)：
    
      update emp set deptno = (select deptno from dept where loc='BOSTON')
      where sal < 平均工资;
      
      
    
    
    
    
    
    
      
      
    删除:
    
     delete from 表名;             删除整张表的数据
     
     delete from 表名 where ……;    删除符合where条件的数据
     
     delete from emp2 where deptno = 10;
     
     select * from emp2;
    
    
    
    
    
    
    
    
    
    
    
    数据库事务:
    
    
     事务由一句DDL语句或一组DML语句组成；
     
     DDL事务 create alter drop truncate
     
     DML事务 insert update delete
     
     
     DML事务，以执行第一句DML语句为开始，以手动commit/rollback为结束
     
     DDL事务，语句执行结果是自动提交commit，不能rollback
     
     DML事务---锁
     
     DML语句执行之后，commit之前：
     
     1)当前用户/当前窗口能够看到语句执行结果
     
     2)其他用户窗口看不到
     
     3)结果是可以回退的(rollback)
     
     4)数据状态，加锁的状态--资源争用
     
     ---锁的处理 sysdba
     update emp set sal = 9000 where deptno =10;
     
     select * from emp;