SQL*Plus break与compute的简单用法
在SQL*Plus提示符下输出求和报表，我们可以借助break与compute两个命令来实现。这个两个命令简单易用，可满足日常需求，其实质也相当于在编写SQL语句时使用分组及聚合函数。不同的是在报表中的分组的最下方或整个报表的最下方我们可以得到如sum,avg以及自定义的聚合字样。
一、break用法：
help break
BREAK
-----
Specifies where changes occur in a report and the formatting
action to perform, such as:
- suppressing display of duplicate values for a given column
- skipping a line each time a given column value changes
(In iSQL*Plus, only when Preformatted Output is ON)
- printing computed figures each time a given column value changes or at the end of the report.
Enter BREAK with no clauses to list the current BREAK definition.
BRE[AK] [ON report_element [action [action]]] ...
where report_element has the following syntax:
{column | expression | ROW | REPORT}
and where action has the following syntax:
[SKI[P] n | [SKI[P]] PAGE] [NODUP[LICATES] | DUP[LICATES]]
The SKIP option is not supported in iSQL*Plus
b、命令特性描述
break 命令主要用于过滤重复列，正如单词所表达的意思及中断，也就是说中断显示重复的列。
当下一行记录的上指定的列与上一行相同，不显示该列，否则显示该列。
当使用break时，通常建议sql语句使用Order by 子句。可以基于order by子句使用多个列，同样break 也可以使用多个列。
report_element表明可以基于列，表达式，行，以及report等多种不同类型来进行中断显示，也就是说break on对哪个进行分组。
action则表示
skip[n],在每个分组的最后，自动跳过n个空行。
skip page, 在每个分组的最后，自动换页。
break on row skip[n],每一行后面跳过n个空行。
nodup 重复的显示空，dup重复的也显示,不加该选项，默认就为nodup
SQL> conn scott/tiger@rhel201; 已连接。 SQL> show pagesize pagesize 50 SQL> show linesize linesize 150 SQL> select deptno,ename,sal from emp order by deptno; DEPTNO ENAME SAL ---------- ---------- ---------- 10 CLARK 2450 10 KING 5000 10 MILLER 1300 20 JONES 2975 20 FORD 3000 20 ADAMS 1100 20 SMITH 800 20 SCOTT 3000 30 WARD 1250 30 TURNER 1500 30 ALLEN 1600 30 JAMES 950 30 BLAKE 2850 30 MARTIN 1250 已选择14行。 SQL> break on deptno --过滤重复的deptno内容，默认为nudup SQL> break --查看当前的break设置信息 break on deptno nodup SQL> list 1* select deptno,ename,sal from emp order by deptno SQL> / DEPTNO ENAME SAL ---------- ---------- ---------- 10 CLARK 2450 KING 5000 MILLER 1300 20 JONES 2975 FORD 3000 ADAMS 1100 SMITH 800 SCOTT 3000 30 WARD 1250 TURNER 1500 ALLEN 1600 JAMES 950 BLAKE 2850 MARTIN 1250 已选择14行。 SQL> break on deptno skip 1 --在每个分组后自动跳过1个空行 SQL> list 1* select deptno,ename,sal from emp order by deptno SQL> / DEPTNO ENAME SAL ---------- ---------- ---------- 10 CLARK 2450 KING 5000 MILLER 1300 20 JONES 2975 FORD 3000 ADAMS 1100 SMITH 800 SCOTT 3000 30 WARD 1250 TURNER 1500 ALLEN 1600 JAMES 950 BLAKE 2850 MARTIN 1250 已选择14行。 SQL> break on row skip 1 --基于row进行分组，且每行之后也跳过一行 SQL> / DEPTNO ENAME SAL ---------- ---------- ---------- 10 CLARK 2450 10 KING 5000 10 MILLER 1300 20 JONES 2975 20 FORD 3000 20 ADAMS 1100 20 SMITH 800 20 SCOTT 3000 30 WARD 1250 30 TURNER 1500 30 ALLEN 1600 30 JAMES 950 30 BLAKE 2850 30 MARTIN 1250 已选择14行。 SQL> SQL> show pagesize pagesize 10 SQL> break on deptno skip page --基于页面进行跳页 SQL> / DEPTNO ENAME SAL ---------- ---------- ---------- 10 CLARK 2450 KING 5000 MILLER 1300 DEPTNO ENAME SAL ---------- ---------- ---------- 20 JONES 2975 FORD 3000 ADAMS 1100 SMITH 800 SCOTT 3000 DEPTNO ENAME SAL ---------- ---------- ---------- 30 WARD 1250 TURNER 1500 ALLEN 1600 JAMES 950 BLAKE 2850 MARTIN 1250 已选择14行。 SQL> SQL> break on deptno on job skip 1 --基于多列break SQL> select deptno,ename,job,sal from emp order by deptno DEPTNO ENAME JOB SAL ---------- ---------- --------- ---------- 10 CLARK MANAGER 2450 KING PRESIDENT 5000 MILLER CLERK 1300 20 JONES MANAGER 2975 DEPTNO ENAME JOB SAL ---------- ---------- --------- ---------- 20 FORD ANALYST 3000 ADAMS CLERK 1100 SMITH 800 SCOTT ANALYST 3000 DEPTNO ENAME JOB SAL ---------- ---------- --------- ---------- 30 WARD SALESMAN 1250 TURNER 1500 ALLEN 1600 JAMES CLERK 950 DEPTNO ENAME JOB SAL ---------- ---------- --------- ---------- 30 BLAKE MANAGER 2850 MARTIN SALESMAN 1250
二、compute用法
help compute
COMPUTE
-------
In combination with the BREAK command, calculates and prints summary lines using various standard computations. Also lists
all COMPUTE definitions.
COMP[UTE] [function [LAB[EL] text] ...
OF {expr|column|alias} ...
ON {expr|column|alias|REPORT|ROW} ...]
b、命令特性描述
compute用于分组值计算指定的列上的数值，实际上等同于对分组列执行group by，然后调用聚合函数。
function为常用的聚合函数，如sum,avg,maximum,minimum,std,count等等。
of为指定的计算列，也就是说要计算哪一列。
on为分组条件，基于哪个列，表达式，report，row等进行分组。
compute通常结合break来用，否则相当于没有分组，聚合也就没有任何意义。
SQL> clear break breaks 已清除 SQL> break on deptno skip 1 SQL> compute sum of sal on deptno; --基于deptno对sal求和 SQL> select deptno,ename,job,sal from emp order by deptno; DEPTNO ENAME JOB SAL ---------- ---------- --------- ---------- 10 CLARK MANAGER 2450 KING PRESIDENT 5000 MILLER CLERK 1300 ********** ---------- sum 8750 20 JONES MANAGER 2975 DEPTNO ENAME JOB SAL ---------- ---------- --------- ---------- 20 FORD ANALYST 3000 ADAMS CLERK 1100 SMITH CLERK 800 SCOTT ANALYST 3000 ********** ---------- sum 10875 DEPTNO ENAME JOB SAL ---------- ---------- --------- ---------- 30 WARD SALESMAN 1250 TURNER SALESMAN 1500 ALLEN SALESMAN 1600 JAMES CLERK 950 BLAKE MANAGER 2850 MARTIN SALESMAN 1250 ********** ---------- DEPTNO ENAME JOB SAL ---------- ---------- --------- ---------- sum 9400 已选择14行。 SQL> SQL> show pagesize pagesize 10 SQL> break on report skip 1 SQL> compute sum of sal on report --基于整个report的sal进行求和 SQL> / DEPTNO ENAME JOB SAL ---------- ---------- --------- ---------- 10 CLARK MANAGER 2450 10 KING PRESIDENT 5000 10 MILLER CLERK 1300 20 JONES MANAGER 2975 20 FORD ANALYST 3000 20 ADAMS CLERK 1100 20 SMITH CLERK 800 DEPTNO ENAME JOB SAL ---------- ---------- --------- ---------- 20 SCOTT ANALYST 3000 30 WARD SALESMAN 1250 30 TURNER SALESMAN 1500 30 ALLEN SALESMAN 1600 30 JAMES CLERK 950 30 BLAKE MANAGER 2850 30 MARTIN SALESMAN 1250 DEPTNO ENAME JOB SAL ---------- ---------- --------- ---------- sum 29025 已选择14行。 SQL> compute sum avg of sal on report ------对整个report求和以及求平均 SQL> / DEPTNO ENAME JOB SAL ---------- ---------- --------- ---------- 10 CLARK MANAGER 2450 10 KING PRESIDENT 5000 10 MILLER CLERK 1300 20 JONES MANAGER 2975 20 FORD ANALYST 3000 20 ADAMS CLERK 1100 20 SMITH CLERK 800 DEPTNO ENAME JOB SAL ---------- ---------- --------- ---------- 20 SCOTT ANALYST 3000 30 WARD SALESMAN 1250 30 TURNER SALESMAN 1500 30 ALLEN SALESMAN 1600 30 JAMES CLERK 950 30 BLAKE MANAGER 2850 30 MARTIN SALESMAN 1250 DEPTNO ENAME JOB SAL ---------- ---------- --------- ---------- ---------- avg 2073.21429 sum 29025 已选择14行。 SQL> SQL> compute sum avg of sal on deptno --对deptno分组进行求和，未平均值 SQL> clear break breaks 已清除 SQL> break on deptno skip 1 SQL> list 1* select deptno,ename,job,sal from emp order by deptno SQL> / DEPTNO ENAME JOB SAL ---------- ---------- --------- ---------- 10 CLARK MANAGER 2450 KING PRESIDENT 5000 MILLER CLERK 1300 ********** ---------- avg 2916.66667 sum 8750 DEPTNO ENAME JOB SAL ---------- ---------- --------- ---------- 20 JONES MANAGER 2975 FORD ANALYST 3000 ADAMS CLERK 1100 SMITH CLERK 800 SCOTT ANALYST 3000 ********** ---------- avg 2175 DEPTNO ENAME JOB SAL ---------- ---------- --------- ---------- sum 10875 30 WARD SALESMAN 1250 TURNER SALESMAN 1500 ALLEN SALESMAN 1600 JAMES CLERK 950 BLAKE MANAGER 2850 DEPTNO ENAME JOB SAL ---------- ---------- --------- ---------- 30 MARTIN SALESMAN 1250 ********** ---------- avg 1566.66667 sum 9400 已选择14行。 SQL> SQL> break on deptno skip 1 SQL> compute sum of sal comm on deptno --对sal及comm基于分组deptno同时求和 SQL> select deptno,ename,sal,job,comm from emp order by deptno DEPTNO ENAME SAL JOB COMM ---------- ---------- ---------- --------- ---------- 10 CLARK 2450 MANAGER 200 KING 5000 PRESIDENT MILLER 1300 CLERK 100 ********** ---------- ---------- sum 8750 300 20 JONES 2975 MANAGER DEPTNO ENAME SAL JOB COMM ---------- ---------- ---------- --------- ---------- 20 FORD 3000 ANALYST ADAMS 1100 CLERK SMITH 800 CLERK 999 SCOTT 3000 ANALYST ********** ---------- ---------- sum 10875 999 DEPTNO ENAME SAL JOB COMM ---------- ---------- ---------- --------- ---------- 30 WARD 1250 SALESMAN 500 TURNER 1500 SALESMAN 0 ALLEN 1600 SALESMAN 300 JAMES 950 CLERK BLAKE 2850 MANAGER MARTIN 1250 SALESMAN 1400 ********** ---------- ---------- DEPTNO ENAME SAL JOB COMM ---------- ---------- ---------- --------- ---------- sum 9400 2200 已选择14行。 SQL> SQL> compute sum avg of sal comm on deptno --基于dpetno，对sal和comm求和，求平均值 SQL> / DEPTNO ENAME SAL JOB COMM ---------- ---------- ---------- --------- ---------- 10 CLARK 2450 MANAGER 200 KING 5000 PRESIDENT MILLER 1300 CLERK 100 ********** ---------- ---------- avg 2916.66667 150 sum 8750 300 DEPTNO ENAME SAL JOB COMM ---------- ---------- ---------- --------- ---------- 20 JONES 2975 MANAGER FORD 3000 ANALYST ADAMS 1100 CLERK SMITH 800 CLERK 999 SCOTT 3000 ANALYST ********** ---------- ---------- avg 2175 999 DEPTNO ENAME SAL JOB COMM ---------- ---------- ---------- --------- ---------- sum 10875 999 30 WARD 1250 SALESMAN 500 TURNER 1500 SALESMAN 0 ALLEN 1600 SALESMAN 300 JAMES 950 CLERK BLAKE 2850 MANAGER DEPTNO ENAME SAL JOB COMM ---------- ---------- ---------- --------- ---------- 30 MARTIN 1250 SALESMAN 1400 ********** ---------- ---------- avg 1566.66667 550 sum 9400 2200 已选择14行。 SQL> SQL> compute avg of sal on deptno --对sal列基于分组deptno求平均值 SQL> compute sum of comm on deptno --对comm列基于分组deptno求和 SQL> list 1* select deptno,ename,sal,job,comm from emp order by deptno SQL> / DEPTNO ENAME SAL JOB COMM ---------- ---------- ---------- --------- ---------- 10 CLARK 2450 MANAGER 200 KING 5000 PRESIDENT MILLER 1300 CLERK 100 ********** ---------- ---------- avg 2916.66667 sum 300 DEPTNO ENAME SAL JOB COMM ---------- ---------- ---------- --------- ---------- 20 JONES 2975 MANAGER FORD 3000 ANALYST ADAMS 1100 CLERK SMITH 800 CLERK 999 SCOTT 3000 ANALYST ********** ---------- ---------- avg 2175 DEPTNO ENAME SAL JOB COMM ---------- ---------- ---------- --------- ---------- sum 999 30 WARD 1250 SALESMAN 500 TURNER 1500 SALESMAN 0 ALLEN 1600 SALESMAN 300 JAMES 950 CLERK BLAKE 2850 MANAGER DEPTNO ENAME SAL JOB COMM ---------- ---------- ---------- --------- ---------- 30 MARTIN 1250 SALESMAN 1400 ********** ---------- ---------- avg 1566.66667 sum 2200 已选择14行。 SQL>