过滤和排序·下

标签：

SQL> /*
SQL> sql 优化2：
SQL>     where条件优化：
SQL>          执行的顺序是从右往左去执行 where deptno = 10 and ename like ‘%a%‘; or
SQL> */
SQL> -- 排序 order by
SQL> -- 根据员工的sal 排序
SQL> select *
  2  from emp
  3  order by sal;

     EMPNO ENAME                JOB                       MGR HIREDATE         
---------- -------------------- ------------------ ---------- --------------   
       SAL       COMM     DEPTNO                                               
---------- ---------- ----------                                               
      7369 SMITH                CLERK                    7902 17-12月-80       
       800                    20                                               
                                                                               
      7900 JAMES                CLERK                    7698 03-12月-81       
       950                    30                                               
                                                                               
      7876 ADAMS                CLERK                    7788 23-5月 -87       
      1100                    20                                               
                                                                               

     EMPNO ENAME                JOB                       MGR HIREDATE         
---------- -------------------- ------------------ ---------- --------------   
       SAL       COMM     DEPTNO                                               
---------- ---------- ----------                                               
      7521 WARD                 SALESMAN                 7698 22-2月 -81       
      1250        500         30                                               
                                                                               
      7654 MARTIN               SALESMAN                 7698 28-9月 -81       
      1250       1400         30                                               
                                                                               
      7934 MILLER               CLERK                    7782 23-1月 -82       
      1300                    10                                               
                                                                               

     EMPNO ENAME                JOB                       MGR HIREDATE         
---------- -------------------- ------------------ ---------- --------------   
       SAL       COMM     DEPTNO                                               
---------- ---------- ----------                                               
      7844 TURNER               SALESMAN                 7698 08-9月 -81       
      1500          0         30                                               
                                                                               
      7499 ALLEN                SALESMAN                 7698 20-2月 -81       
      1600        300         30                                               
                                                                               
      7782 CLARK                MANAGER                  7839 09-6月 -81       
      2450                    10                                               
                                                                               

     EMPNO ENAME                JOB                       MGR HIREDATE         
---------- -------------------- ------------------ ---------- --------------   
       SAL       COMM     DEPTNO                                               
---------- ---------- ----------                                               
      7698 BLAKE                MANAGER                  7839 01-5月 -81       
      2850                    30                                               
                                                                               
      7566 JONES                MANAGER                  7839 02-4月 -81       
      2975                    20                                               
                                                                               
      7788 SCOTT                ANALYST                  7566 19-4月 -87       
      3000                    20                                               
                                                                               

     EMPNO ENAME                JOB                       MGR HIREDATE         
---------- -------------------- ------------------ ---------- --------------   
       SAL       COMM     DEPTNO                                               
---------- ---------- ----------                                               
      7902 FORD                 ANALYST                  7566 03-12月-81       
      3000                    20                                               
                                                                               
      7839 KING                 PRESIDENT                     17-11月-81       
      5000                    10                                               
                                                                               

已选择14行。

SQL> set linesize 200;
SQL> /

     EMPNO ENAME                JOB                       MGR HIREDATE              SAL       COMM     DEPTNO                                                                                          
---------- -------------------- ------------------ ---------- -------------- ---------- ---------- ----------                                                                                          
      7369 SMITH                CLERK                    7902 17-12月-80            800                    20                                                                                          
      7900 JAMES                CLERK                    7698 03-12月-81            950                    30                                                                                          
      7876 ADAMS                CLERK                    7788 23-5月 -87           1100                    20                                                                                          
      7521 WARD                 SALESMAN                 7698 22-2月 -81           1250        500         30                                                                                          
      7654 MARTIN               SALESMAN                 7698 28-9月 -81           1250       1400         30                                                                                          
      7934 MILLER               CLERK                    7782 23-1月 -82           1300                    10                                                                                          
      7844 TURNER               SALESMAN                 7698 08-9月 -81           1500          0         30                                                                                          
      7499 ALLEN                SALESMAN                 7698 20-2月 -81           1600        300         30                                                                                          
      7782 CLARK                MANAGER                  7839 09-6月 -81           2450                    10                                                                                          
      7698 BLAKE                MANAGER                  7839 01-5月 -81           2850                    30                                                                                          
      7566 JONES                MANAGER                  7839 02-4月 -81           2975                    20                                                                                          

     EMPNO ENAME                JOB                       MGR HIREDATE              SAL       COMM     DEPTNO                                                                                          
---------- -------------------- ------------------ ---------- -------------- ---------- ---------- ----------                                                                                          
      7788 SCOTT                ANALYST                  7566 19-4月 -87           3000                    20                                                                                          
      7902 FORD                 ANALYST                  7566 03-12月-81           3000                    20                                                                                          
      7839 KING                 PRESIDENT                     17-11月-81           5000                    10                                                                                          

已选择14行。

SQL> --默认情况下oarcle是按照升序排列
SQL> select *
  2  from emp
  3  order by sal desc;

     EMPNO ENAME                JOB                       MGR HIREDATE              SAL       COMM     DEPTNO                                                                                          
---------- -------------------- ------------------ ---------- -------------- ---------- ---------- ----------                                                                                          
      7839 KING                 PRESIDENT                     17-11月-81           5000                    10                                                                                          
      7902 FORD                 ANALYST                  7566 03-12月-81           3000                    20                                                                                          
      7788 SCOTT                ANALYST                  7566 19-4月 -87           3000                    20                                                                                          
      7566 JONES                MANAGER                  7839 02-4月 -81           2975                    20                                                                                          
      7698 BLAKE                MANAGER                  7839 01-5月 -81           2850                    30                                                                                          
      7782 CLARK                MANAGER                  7839 09-6月 -81           2450                    10                                                                                          
      7499 ALLEN                SALESMAN                 7698 20-2月 -81           1600        300         30                                                                                          
      7844 TURNER               SALESMAN                 7698 08-9月 -81           1500          0         30                                                                                          
      7934 MILLER               CLERK                    7782 23-1月 -82           1300                    10                                                                                          
      7521 WARD                 SALESMAN                 7698 22-2月 -81           1250        500         30                                                                                          
      7654 MARTIN               SALESMAN                 7698 28-9月 -81           1250       1400         30                                                                                          

     EMPNO ENAME                JOB                       MGR HIREDATE              SAL       COMM     DEPTNO                                                                                          
---------- -------------------- ------------------ ---------- -------------- ---------- ---------- ----------                                                                                          
      7876 ADAMS                CLERK                    7788 23-5月 -87           1100                    20                                                                                          
      7900 JAMES                CLERK                    7698 03-12月-81            950                    30                                                                                          
      7369 SMITH                CLERK                    7902 17-12月-80            800                    20                                                                                          

已选择14行。

SQL> select *
  2  from emp
  3  order by sal asc;

     EMPNO ENAME                JOB                       MGR HIREDATE              SAL       COMM     DEPTNO                                                                                          
---------- -------------------- ------------------ ---------- -------------- ---------- ---------- ----------                                                                                          
      7369 SMITH                CLERK                    7902 17-12月-80            800                    20                                                                                          
      7900 JAMES                CLERK                    7698 03-12月-81            950                    30                                                                                          
      7876 ADAMS                CLERK                    7788 23-5月 -87           1100                    20                                                                                          
      7521 WARD                 SALESMAN                 7698 22-2月 -81           1250        500         30                                                                                          
      7654 MARTIN               SALESMAN                 7698 28-9月 -81           1250       1400         30                                                                                          
      7934 MILLER               CLERK                    7782 23-1月 -82           1300                    10                                                                                          
      7844 TURNER               SALESMAN                 7698 08-9月 -81           1500          0         30                                                                                          
      7499 ALLEN                SALESMAN                 7698 20-2月 -81           1600        300         30                                                                                          
      7782 CLARK                MANAGER                  7839 09-6月 -81           2450                    10                                                                                          
      7698 BLAKE                MANAGER                  7839 01-5月 -81           2850                    30                                                                                          
      7566 JONES                MANAGER                  7839 02-4月 -81           2975                    20                                                                                          

     EMPNO ENAME                JOB                       MGR HIREDATE              SAL       COMM     DEPTNO                                                                                          
---------- -------------------- ------------------ ---------- -------------- ---------- ---------- ----------                                                                                          
      7788 SCOTT                ANALYST                  7566 19-4月 -87           3000                    20                                                                                          
      7902 FORD                 ANALYST                  7566 03-12月-81           3000                    20                                                                                          
      7839 KING                 PRESIDENT                     17-11月-81           5000                    10                                                                                          

已选择14行。

SQL> -- desc 降序 asc升序
SQL> -- 按照sal和部门号排序
SQL> select *
  2  from emp
  3  order by sal,deptno;

     EMPNO ENAME                JOB                       MGR HIREDATE              SAL       COMM     DEPTNO                                                                                          
---------- -------------------- ------------------ ---------- -------------- ---------- ---------- ----------                                                                                          
      7369 SMITH                CLERK                    7902 17-12月-80            800                    20                                                                                          
      7900 JAMES                CLERK                    7698 03-12月-81            950                    30                                                                                          
      7876 ADAMS                CLERK                    7788 23-5月 -87           1100                    20                                                                                          
      7521 WARD                 SALESMAN                 7698 22-2月 -81           1250        500         30                                                                                          
      7654 MARTIN               SALESMAN                 7698 28-9月 -81           1250       1400         30                                                                                          
      7934 MILLER               CLERK                    7782 23-1月 -82           1300                    10                                                                                          
      7844 TURNER               SALESMAN                 7698 08-9月 -81           1500          0         30                                                                                          
      7499 ALLEN                SALESMAN                 7698 20-2月 -81           1600        300         30                                                                                          
      7782 CLARK                MANAGER                  7839 09-6月 -81           2450                    10                                                                                          
      7698 BLAKE                MANAGER                  7839 01-5月 -81           2850                    30                                                                                          
      7566 JONES                MANAGER                  7839 02-4月 -81           2975                    20                                                                                          

     EMPNO ENAME                JOB                       MGR HIREDATE              SAL       COMM     DEPTNO                                                                                          
---------- -------------------- ------------------ ---------- -------------- ---------- ---------- ----------                                                                                          
      7788 SCOTT                ANALYST                  7566 19-4月 -87           3000                    20                                                                                          
      7902 FORD                 ANALYST                  7566 03-12月-81           3000                    20                                                                                          
      7839 KING                 PRESIDENT                     17-11月-81           5000                    10                                                                                          

已选择14行。

SQL> select *
  2  from emp
  3  order by job,deptno;

     EMPNO ENAME                JOB                       MGR HIREDATE              SAL       COMM     DEPTNO                                                                                          
---------- -------------------- ------------------ ---------- -------------- ---------- ---------- ----------                                                                                          
      7902 FORD                 ANALYST                  7566 03-12月-81           3000                    20                                                                                          
      7788 SCOTT                ANALYST                  7566 19-4月 -87           3000                    20                                                                                          
      7934 MILLER               CLERK                    7782 23-1月 -82           1300                    10                                                                                          
      7369 SMITH                CLERK                    7902 17-12月-80            800                    20                                                                                          
      7876 ADAMS                CLERK                    7788 23-5月 -87           1100                    20                                                                                          
      7900 JAMES                CLERK                    7698 03-12月-81            950                    30                                                                                          
      7782 CLARK                MANAGER                  7839 09-6月 -81           2450                    10                                                                                          
      7566 JONES                MANAGER                  7839 02-4月 -81           2975                    20                                                                                          
      7698 BLAKE                MANAGER                  7839 01-5月 -81           2850                    30                                                                                          
      7839 KING                 PRESIDENT                     17-11月-81           5000                    10                                                                                          
      7654 MARTIN               SALESMAN                 7698 28-9月 -81           1250       1400         30                                                                                          

     EMPNO ENAME                JOB                       MGR HIREDATE              SAL       COMM     DEPTNO                                                                                          
---------- -------------------- ------------------ ---------- -------------- ---------- ---------- ----------                                                                                          
      7844 TURNER               SALESMAN                 7698 08-9月 -81           1500          0         30                                                                                          
      7521 WARD                 SALESMAN                 7698 22-2月 -81           1250        500         30                                                                                          
      7499 ALLEN                SALESMAN                 7698 20-2月 -81           1600        300         30                                                                                          

已选择14行。

SQL> -- 如果排序后面跟了多个列，那么会首先使用第一列来排，第一列拍出来的，使用第二列来拍，以此类推。
SQL> -- order by 后面能跟什么东西？
SQL> -- order by 列明，别名，表达式，列所在的数字顺序
SQL> select deptno,empno 员工号
  2  from emp
  3  order by 员工号;

    DEPTNO     员工号                                                                                                                                                                                  
---------- ----------                                                                                                                                                                                  
        20       7369                                                                                                                                                                                  
        30       7499                                                                                                                                                                                  
        30       7521                                                                                                                                                                                  
        20       7566                                                                                                                                                                                  
        30       7654                                                                                                                                                                                  
        30       7698                                                                                                                                                                                  
        10       7782                                                                                                                                                                                  
        20       7788                                                                                                                                                                                  
        10       7839                                                                                                                                                                                  
        30       7844                                                                                                                                                                                  
        20       7876                                                                                                                                                                                  

    DEPTNO     员工号                                                                                                                                                                                  
---------- ----------                                                                                                                                                                                  
        30       7900                                                                                                                                                                                  
        20       7902                                                                                                                                                                                  
        10       7934                                                                                                                                                                                  

已选择14行。

SQL> select sal*12 基本工资
  2  from emp
  3  order by sal*12;

  基本工资                                                                                                                                                                                             
----------                                                                                                                                                                                             
      9600                                                                                                                                                                                             
     11400                                                                                                                                                                                             
     13200                                                                                                                                                                                             
     15000                                                                                                                                                                                             
     15000                                                                                                                                                                                             
     15600                                                                                                                                                                                             
     18000                                                                                                                                                                                             
     19200                                                                                                                                                                                             
     29400                                                                                                                                                                                             
     34200                                                                                                                                                                                             
     35700                                                                                                                                                                                             

  基本工资                                                                                                                                                                                             
----------                                                                                                                                                                                             
     36000                                                                                                                                                                                             
     36000                                                                                                                                                                                             
     60000                                                                                                                                                                                             

已选择14行。

SQL> select empno,deptno,sal*12 + nvl(comm,0)
  2  from emp
  3  order by 3;

     EMPNO     DEPTNO SAL*12+NVL(COMM,0)                                                                                                                                                               
---------- ---------- ------------------                                                                                                                                                               
      7369         20               9600                                                                                                                                                               
      7900         30              11400                                                                                                                                                               
      7876         20              13200                                                                                                                                                               
      7521         30              15500                                                                                                                                                               
      7934         10              15600                                                                                                                                                               
      7654         30              16400                                                                                                                                                               
      7844         30              18000                                                                                                                                                               
      7499         30              19500                                                                                                                                                               
      7782         10              29400                                                                                                                                                               
      7698         30              34200                                                                                                                                                               
      7566         20              35700                                                                                                                                                               

     EMPNO     DEPTNO SAL*12+NVL(COMM,0)                                                                                                                                                               
---------- ---------- ------------------                                                                                                                                                               
      7788         20              36000                                                                                                                                                               
      7902         20              36000                                                                                                                                                               
      7839         10              60000                                                                                                                                                               

已选择14行。

SQL> select empno,deptno
  2  from emp
  3  order by empno,depton desc;
order by empno,depton desc
               *
第 3 行出现错误:
ORA-00904: "DEPTON": 标识符无效

SQL> 3
  3* order by empno,depton desc
SQL> c /depton/deptno;
  3* order by empno,deptno desc
SQL> /

     EMPNO     DEPTNO                                                                                                                                                                                  
---------- ----------                                                                                                                                                                                  
      7369         20                                                                                                                                                                                  
      7499         30                                                                                                                                                                                  
      7521         30                                                                                                                                                                                  
      7566         20                                                                                                                                                                                  
      7654         30                                                                                                                                                                                  
      7698         30                                                                                                                                                                                  
      7782         10                                                                                                                                                                                  
      7788         20                                                                                                                                                                                  
      7839         10                                                                                                                                                                                  
      7844         30                                                                                                                                                                                  
      7876         20                                                                                                                                                                                  

     EMPNO     DEPTNO                                                                                                                                                                                  
---------- ----------                                                                                                                                                                                  
      7900         30                                                                                                                                                                                  
      7902         20                                                                                                                                                                                  
      7934         10                                                                                                                                                                                  

已选择14行。

SQL> select job,deptno
  2  from emp
  3  order by job,deptno desc;

JOB                    DEPTNO                                                                                                                                                                          
------------------ ----------                                                                                                                                                                          
ANALYST                    20                                                                                                                                                                          
ANALYST                    20                                                                                                                                                                          
CLERK                      30                                                                                                                                                                          
CLERK                      20                                                                                                                                                                          
CLERK                      20                                                                                                                                                                          
CLERK                      10                                                                                                                                                                          
MANAGER                    30                                                                                                                                                                          
MANAGER                    20                                                                                                                                                                          
MANAGER                    10                                                                                                                                                                          
PRESIDENT                  10                                                                                                                                                                          
SALESMAN                   30                                                                                                                                                                          

JOB                    DEPTNO                                                                                                                                                                          
------------------ ----------                                                                                                                                                                          
SALESMAN                   30                                                                                                                                                                          
SALESMAN                   30                                                                                                                                                                          
SALESMAN                   30                                                                                                                                                                          

已选择14行。

SQL> -- desc只用用于理他最近的那一列
SQL> select empno,comm
  2  from emp
  3  order by comm desc;

     EMPNO       COMM                                                                                                                                                                                  
---------- ----------                                                                                                                                                                                  
      7369                                                                                                                                                                                             
      7782                                                                                                                                                                                             
      7902                                                                                                                                                                                             
      7900                                                                                                                                                                                             
      7876                                                                                                                                                                                             
      7566                                                                                                                                                                                             
      7698                                                                                                                                                                                             
      7934                                                                                                                                                                                             
      7788                                                                                                                                                                                             
      7839                                                                                                                                                                                             
      7654       1400                                                                                                                                                                                  

     EMPNO       COMM                                                                                                                                                                                  
---------- ----------                                                                                                                                                                                  
      7521        500                                                                                                                                                                                  
      7499        300                                                                                                                                                                                  
      7844          0                                                                                                                                                                                  

已选择14行。

SQL> -- 在oracle中null最大
SQL> -- 让null在最后显示
SQL> select empno,comm
  2  from emp
  3  order by comm desc
  4  nulls last;

     EMPNO       COMM                                                                                                                                                                                  
---------- ----------                                                                                                                                                                                  
      7654       1400                                                                                                                                                                                  
      7521        500                                                                                                                                                                                  
      7499        300                                                                                                                                                                                  
      7844          0                                                                                                                                                                                  
      7788                                                                                                                                                                                             
      7839                                                                                                                                                                                             
      7876                                                                                                                                                                                             
      7900                                                                                                                                                                                             
      7902                                                                                                                                                                                             
      7934                                                                                                                                                                                             
      7698                                                                                                                                                                                             

     EMPNO       COMM                                                                                                                                                                                  
---------- ----------                                                                                                                                                                                  
      7566                                                                                                                                                                                             
      7369                                                                                                                                                                                             
      7782                                                                                                                                                                                             

已选择14行。

SQL> spool off;

过滤和排序·下

标签：

原文地址：http://www.cnblogs.com/877599949yan/p/5284994.html