Oracle PL/SQL Tutorial/Numerical Math Functions/ROUND — различия между версиями

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Текущая версия на 10:08, 26 мая 2010

Demonstrates the ROUND function

SQL>
SQL> SET SERVEROUTPUT ON
SQL> DECLARE
  2     v_round NUMBER (10,4) := 12345.6789;
  3  BEGIN
  4
  5     DBMS_OUTPUT.PUT_LINE("Default: "||ROUND(v_round));
  6     DBMS_OUTPUT.PUT_LINE("+2: "||ROUND(v_round, 2));
  7     DBMS_OUTPUT.PUT_LINE("-2: "||ROUND(v_round, -2));
  8
  9  END;
 10  /
Default: 12346
+2: 12345.68
-2: 12300
PL/SQL procedure successfully completed.
SQL>
SQL>


ROUND(345.678,2) ROUND(345.678,-1) ROUND(345.678,-2)

SQL>
SQL>
SQL> select round(345.678,2)
  2  ,      round(345.678,-1)
  3  ,      round(345.678,-2)
  4  from   dual;
ROUND(345.678,2) ROUND(345.678,-1) ROUND(345.678,-2)
---------------- ----------------- -----------------
          345.68               350               300
SQL>


ROUND(5.75)

SQL> select ROUND(5.75) from dual;
ROUND(5.75)
-----------
          6


ROUND(

SQL> select ROUND(5.75, 1) from dual;
ROUND(5.75,1)
-------------
          5.8


ROUND(5.75, -1) (2)

SQL> select ROUND(5.75, -1) from dual;
ROUND(5.75,-1)
--------------
            10


ROUND column value

SQL> -- create demo table
SQL> create table myTable(
  2    id           NUMBER(2),
  3    value        NUMBER(6,2)
  4  )
  5  /
Table created.
SQL>
SQL> -- prepare data
SQL> insert into myTable(ID,  value)values (1,9)
  2  /
1 row created.
SQL> insert into myTable(ID,  value)values (2,2.11)
  2  /
1 row created.
SQL> insert into myTable(ID,  value)values (3,3.44)
  2  /
1 row created.
SQL> insert into myTable(ID,  value)values (4,-4.21)
  2  /
1 row created.
SQL> insert into myTable(ID,  value)values (5,10)
  2  /
1 row created.
SQL> insert into myTable(ID,  value)values (6,3)
  2  /
1 row created.
SQL> insert into myTable(ID,  value)values (7,-5.88)
  2  /
1 row created.
SQL> insert into myTable(ID,  value)values (8,123.45)
  2  /
1 row created.
SQL> insert into myTable(ID,  value)values (9,98.23)
  2  /
1 row created.
SQL>
SQL> select * from myTable
  2  /
        ID      VALUE
---------- ----------
         1          9
         2       2.11
         3       3.44
         4      -4.21
         5         10
         6          3
         7      -5.88
         8     123.45
         9      98.23
9 rows selected.
SQL>
SQL> SELECT id, value, ROUND(value) FROM myTable
  2  /
        ID      VALUE ROUND(VALUE)
---------- ---------- ------------
         1          9            9
         2       2.11            2
         3       3.44            3
         4      -4.21           -4
         5         10           10
         6          3            3
         7      -5.88           -6
         8     123.45          123
         9      98.23           98
9 rows selected.
SQL>
SQL>
SQL>
SQL> -- clean the table
SQL> drop table myTable
  2  /
Table dropped.
SQL>
SQL>


ROUND for negative value

"Next highest absolute value" for negative numbers rounds to the negative value of the appropriate absolute value of the negative number; e.g., ROUND(6.8) = 7



SQL>
SQL>
SQL> -- create demo table
SQL> create table myTable(
  2    id           NUMBER(2),
  3    value        NUMBER(6,2)
  4  )
  5  /
Table created.
SQL>
SQL> -- prepare data
SQL> insert into myTable(ID,  value)values (1,9)
  2  /
1 row created.
SQL> insert into myTable(ID,  value)values (2,2.11)
  2  /
1 row created.
SQL> insert into myTable(ID,  value)values (3,3.44)
  2  /
1 row created.
SQL> insert into myTable(ID,  value)values (4,-4.21)
  2  /
1 row created.
SQL> insert into myTable(ID,  value)values (5,10)
  2  /
1 row created.
SQL> insert into myTable(ID,  value)values (6,3)
  2  /
1 row created.
SQL> insert into myTable(ID,  value)values (7,-5.88)
  2  /
1 row created.
SQL> insert into myTable(ID,  value)values (8,123.45)
  2  /
1 row created.
SQL> insert into myTable(ID,  value)values (9,98.23)
  2  /
1 row created.
SQL>
SQL> select * from myTable
  2  /
        ID      VALUE
---------- ----------
         1          9
         2       2.11
         3       3.44
         4      -4.21
         5         10
         6          3
         7      -5.88
         8     123.45
         9      98.23
9 rows selected.
SQL>
SQL>
SQL> SELECT id, value,ROUND(value) FROM myTable
  2  /
        ID      VALUE ROUND(VALUE)
---------- ---------- ------------
         1          9            9
         2       2.11            2
         3       3.44            3
         4      -4.21           -4
         5         10           10
         6          3            3
         7      -5.88           -6
         8     123.45          123
         9      98.23           98
9 rows selected.
SQL>
SQL>
SQL>
SQL>
SQL> -- clean the table
SQL> drop table myTable
  2  /
Table dropped.
SQL>
SQL>


ROUND may have a second argument to handle precision: means the distance to the right of the decimal point

SQL>
SQL> -- create demo table
SQL> create table myTable(
  2    id           NUMBER(2),
  3    value        NUMBER(6,2)
  4  )
  5  /
Table created.
SQL>
SQL> -- prepare data
SQL> insert into myTable(ID,  value)values (1,9)
  2  /
1 row created.
SQL> insert into myTable(ID,  value)values (2,2.11)
  2  /
1 row created.
SQL> insert into myTable(ID,  value)values (3,3.44)
  2  /
1 row created.
SQL> insert into myTable(ID,  value)values (4,-4.21)
  2  /
1 row created.
SQL> insert into myTable(ID,  value)values (5,10)
  2  /
1 row created.
SQL> insert into myTable(ID,  value)values (6,3)
  2  /
1 row created.
SQL> insert into myTable(ID,  value)values (7,-5.88)
  2  /
1 row created.
SQL> insert into myTable(ID,  value)values (8,123.45)
  2  /
1 row created.
SQL> insert into myTable(ID,  value)values (9,98.23)
  2  /
1 row created.
SQL>
SQL> select * from myTable
  2  /
        ID      VALUE
---------- ----------
         1          9
         2       2.11
         3       3.44
         4      -4.21
         5         10
         6          3
         7      -5.88
         8     123.45
         9      98.23
9 rows selected.
SQL>
SQL>
SQL> SELECT id, value, ROUND(value,1)FROM myTable
  2  /
        ID      VALUE ROUND(VALUE,1)
---------- ---------- --------------
         1          9              9
         2       2.11            2.1
         3       3.44            3.4
         4      -4.21           -4.2
         5         10             10
         6          3              3
         7      -5.88           -5.9
         8     123.45          123.5
         9      98.23           98.2
9 rows selected.
SQL>
SQL>
SQL> -- clean the table
SQL> drop table myTable
  2  /
Table dropped.
SQL>


round(sqrt(sal),2)

SQL> CREATE TABLE EMP(
  2      EMPNO NUMBER(4) NOT NULL,
  3      ENAME VARCHAR2(10),
  4      JOB VARCHAR2(9),
  5      MGR NUMBER(4),
  6      HIREDATE DATE,
  7      SAL NUMBER(7, 2),
  8      COMM NUMBER(7, 2),
  9      DEPTNO NUMBER(2)
 10  );
Table created.
SQL>
SQL> INSERT INTO EMP VALUES(7369, "SMITH", "CLERK", 7902,TO_DATE("17-DEC-1980", "DD-MON-YYYY"), 800, NULL, 20);
1 row created.
SQL> INSERT INTO EMP VALUES(7499, "ALLEN", "SALESMAN", 7698,TO_DATE("20-FEB-1981", "DD-MON-YYYY"), 1600, 300, 30);
1 row created.
SQL> INSERT INTO EMP VALUES(7521, "WARD", "SALESMAN", 7698,TO_DATE("22-FEB-1981", "DD-MON-YYYY"), 1250, 500, 30);
1 row created.
SQL> INSERT INTO EMP VALUES(7566, "JONES", "MANAGER", 7839,TO_DATE("2-APR-1981", "DD-MON-YYYY"), 2975, NULL, 20);
1 row created.
SQL> INSERT INTO EMP VALUES(7654, "MARTIN", "SALESMAN", 7698,TO_DATE("28-SEP-1981", "DD-MON-YYYY"), 1250, 1400, 30);
1 row created.
SQL> INSERT INTO EMP VALUES(7698, "BLAKE", "MANAGER", 7839,TO_DATE("1-MAY-1981", "DD-MON-YYYY"), 2850, NULL, 30);
1 row created.
SQL> INSERT INTO EMP VALUES(7782, "CLARK", "MANAGER", 7839,TO_DATE("9-JUN-1981", "DD-MON-YYYY"), 2450, NULL, 10);
1 row created.
SQL> INSERT INTO EMP VALUES(7788, "SCOTT", "ANALYST", 7566,TO_DATE("09-DEC-1982", "DD-MON-YYYY"), 3000, NULL, 20);
1 row created.
SQL> INSERT INTO EMP VALUES(7839, "KING", "PRESIDENT", NULL,TO_DATE("17-NOV-1981", "DD-MON-YYYY"), 5000, NULL, 10);
1 row created.
SQL> INSERT INTO EMP VALUES(7844, "TURNER", "SALESMAN", 7698,TO_DATE("8-SEP-1981", "DD-MON-YYYY"), 1500, 0, 30);
1 row created.
SQL> INSERT INTO EMP VALUES(7876, "ADAMS", "CLERK", 7788,TO_DATE("12-JAN-1983", "DD-MON-YYYY"), 1100, NULL, 20);
1 row created.
SQL> INSERT INTO EMP VALUES(7900, "JAMES", "CLERK", 7698,TO_DATE("3-DEC-1981", "DD-MON-YYYY"), 950, NULL, 30);
1 row created.
SQL> INSERT INTO EMP VALUES(7902, "FORD", "ANALYST", 7566,TO_DATE("3-DEC-1981", "DD-MON-YYYY"), 3000, NULL, 20);
1 row created.
SQL> INSERT INTO EMP VALUES(7934, "MILLER", "CLERK", 7782,TO_DATE("23-JAN-1982", "DD-MON-YYYY"), 1300, NULL, 10);
1 row created.
SQL>
SQL>
SQL> select ename, sal, round(sqrt(sal),2) "Bonus" from emp;
ENAME             SAL      Bonus
---------- ---------- ----------
SMITH             800      28.28
ALLEN            1600         40
WARD             1250      35.36
JONES            2975      54.54
MARTIN           1250      35.36
BLAKE            2850      53.39
CLARK            2450       49.5
SCOTT            3000      54.77
KING             5000      70.71
TURNER           1500      38.73
ADAMS            1100      33.17
ENAME             SAL      Bonus
---------- ---------- ----------
JAMES             950      30.82
FORD             3000      54.77
MILLER           1300      36.06
14 rows selected.
SQL>
SQL> drop table emp;
Table dropped.


ROUND(x, [y]) gets the result of rounding x an optional y decimal places.

If y is omitted, x is rounded to zero decimal places.

If y is negative, x is rounded to the left of the decimal point.

The following example uses ROUND() to display the result of rounding 5.75 to zero, 1, and -1 decimal places, respectively:



SQL>
SQL> SELECT ROUND(5.75), ROUND(5.75, 1), ROUND(5.75, -1) FROM dual;
ROUND(5.75) ROUND(5.75,1) ROUND(5.75,-1)
----------- ------------- --------------
          6           5.8             10
SQL>
SQL>


The second argument of ROUND defaults to 0

SQL> -- create demo table
SQL> create table myTable(
  2    id           NUMBER(2),
  3    value        NUMBER(6,2)
  4  )
  5  /
Table created.
SQL>
SQL> -- prepare data
SQL> insert into myTable(ID,  value)values (1,9)
  2  /
1 row created.
SQL> insert into myTable(ID,  value)values (2,2.11)
  2  /
1 row created.
SQL> insert into myTable(ID,  value)values (3,3.44)
  2  /
1 row created.
SQL> insert into myTable(ID,  value)values (4,-4.21)
  2  /
1 row created.
SQL> insert into myTable(ID,  value)values (5,10)
  2  /
1 row created.
SQL> insert into myTable(ID,  value)values (6,3)
  2  /
1 row created.
SQL> insert into myTable(ID,  value)values (7,-5.88)
  2  /
1 row created.
SQL> insert into myTable(ID,  value)values (8,123.45)
  2  /
1 row created.
SQL> insert into myTable(ID,  value)values (9,98.23)
  2  /
1 row created.
SQL>
SQL> select * from myTable
  2  /
        ID      VALUE
---------- ----------
         1          9
         2       2.11
         3       3.44
         4      -4.21
         5         10
         6          3
         7      -5.88
         8     123.45
         9      98.23
9 rows selected.
SQL>
SQL> SELECT id, value, ROUND(value,0), ROUND(value) FROM myTable
  2  /
        ID      VALUE ROUND(VALUE,0) ROUND(VALUE)
---------- ---------- -------------- ------------
         1          9              9            9
         2       2.11              2            2
         3       3.44              3            3
         4      -4.21             -4           -4
         5         10             10           10
         6          3              3            3
         7      -5.88             -6           -6
         8     123.45            123          123
         9      98.23             98           98
9 rows selected.
SQL>
SQL> -- clean the table
SQL> drop table myTable
  2  /
Table dropped.
SQL>


The second argument of ROUND, precision, may be negative, which means displacement to the left of the decimal point

SQL>
SQL> -- create demo table
SQL> create table myTable(
  2    id           NUMBER(2),
  3    value        NUMBER(6,2)
  4  )
  5  /
Table created.
SQL>
SQL> -- prepare data
SQL> insert into myTable(ID,  value)values (1,9)
  2  /
1 row created.
SQL> insert into myTable(ID,  value)values (2,2.11)
  2  /
1 row created.
SQL> insert into myTable(ID,  value)values (3,3.44)
  2  /
1 row created.
SQL> insert into myTable(ID,  value)values (4,-4.21)
  2  /
1 row created.
SQL> insert into myTable(ID,  value)values (5,10)
  2  /
1 row created.
SQL> insert into myTable(ID,  value)values (6,3)
  2  /
1 row created.
SQL> insert into myTable(ID,  value)values (7,-5.88)
  2  /
1 row created.
SQL> insert into myTable(ID,  value)values (8,123.45)
  2  /
1 row created.
SQL> insert into myTable(ID,  value)values (9,98.23)
  2  /
1 row created.
SQL>
SQL> select * from myTable
  2  /
        ID      VALUE
---------- ----------
         1          9
         2       2.11
         3       3.44
         4      -4.21
         5         10
         6          3
         7      -5.88
         8     123.45
         9      98.23
9 rows selected.
SQL>
SQL> SELECT id, value, ROUND(value,-1) FROM myTable
  2  /
        ID      VALUE ROUND(VALUE,-1)
---------- ---------- ---------------
         1          9              10
         2       2.11               0
         3       3.44               0
         4      -4.21               0
         5         10              10
         6          3               0
         7      -5.88             -10
         8     123.45             120
         9      98.23             100
9 rows selected.
SQL>
SQL>
SQL>
SQL> -- clean the table
SQL> drop table myTable
  2  /
Table dropped.
SQL>