Oracle PL/SQL Tutorial/Numerical Math Functions/SIGN

SIGN(0)

SQL> select SIGN(0) from dual;
   SIGN(0)
----------
         0

SIGN(-5)

SQL> select SIGN(-5) from dual;
  SIGN(-5)
----------
        -1

SIGN(5) (2)

SQL> select SIGN(5) from dual;
   SIGN(5)
----------
         1

SIGN(x) gets the sign of x. SIGN() returns -1 if x is negative, 1 if x is positive, or 0 if x is zero.

The following example displays the sign of -5, 5, and 0, respectively:

SQL>
SQL> SELECT SIGN(-5), SIGN(5), SIGN(0) FROM dual;
  SIGN(-5)    SIGN(5)    SIGN(0)
---------- ---------- ----------
        -1          1          0
SQL>

Use SIGN function to deal with column data

SQL>
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> SELECT id, value, SIGN(value) FROM myTable
  2  /
        ID      VALUE SIGN(VALUE)
---------- ---------- -----------
         1          9           1
         2       2.11           1
         3       3.44           1
         4      -4.21          -1
         5         10           1
         6          3           1
         7      -5.88          -1
         8     123.45           1
         9      98.23           1
9 rows selected.
SQL>
SQL>
SQL>
SQL> -- clean the table
SQL> drop table myTable
  2  /
Table dropped.
SQL>
SQL>