Oracle PL/SQL/Numeric Math Functions/SQRT

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Версия от 09:55, 26 мая 2010; Admin (обсуждение | вклад) (1 версия)
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Get the square root

 
SQL>
SQL> -- create demo table
SQL> create table TestTable(
  2    ID                 VARCHAR2(4 BYTE)         NOT NULL,
  3    MyName             VARCHAR2(10 BYTE),
  4    MyDate             DATE,
  5    MyNumber           Number(8,2)
  6  )
  7  /
Table created.
SQL>
SQL>
SQL> insert into TestTable (ID, MyName, MyDate, MyNumber) values("1","Alison",to_date("19960711","YYYYMMDD"),12.12);
1 row created.
SQL> insert into TestTable (ID, MyName, MyDate, MyNumber) values("3","Smith",to_date("19980513","YYYYMMDD"),22.1);
1 row created.
SQL> insert into TestTable (ID, MyName, MyDate, MyNumber) values("5","Darlene",to_date("20000415","YYYYMMDD"),2.1);
1 row created.
SQL>
SQL>
SQL> select * from TestTable;
ID   MYNAME     MYDATE      MYNUMBER
---- ---------- --------- ----------
1    Alison     11-JUL-96      12.12
3    Smith      13-MAY-98       22.1
5    Darlene    15-APR-00        2.1
SQL>
SQL>
SQL> SELECT MyNumber, SQRT(MyNumber) FROM TestTable;
  MYNUMBER SQRT(MYNUMBER)
---------- --------------
     12.12     3.48137904
      22.1     4.70106371
       2.1     1.44913767
SQL>
SQL>
SQL> drop table TestTable;
Table dropped.
SQL>
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.



SQRT(5)

 
SQL> select SQRT(5) from dual;
   SQRT(5)
----------
2.23606798
SQL>



SQRT() extracts the square root from the input argument.

  
SQL>
Syntax: SQRT(<numeric expression>)
SQL>
SQL>
SQL> SELECT
  2     SQRT(100) root from dual;
      ROOT
----------
        10



SQRT(x): Returns the square root of x

 
SQL> --SQRT(x): Returns the square root of x.
SQL>
SQL> select SQRT(25) from dual;
  SQRT(25)
----------
         5
SQL>