1. SQL Reference Guide
  2. Built-in Functions
  3. Functions of Mathematical Operations
  4. sign function

sign function

The sign function returns the sign of the specified expression, that is, zero if the argument is zero, 1 if the argument is greater than zero, and -1 if the argument is less than zero.

Syntax:

double sign(n)

Semantics:

  • n: The argument n is an expression that resolves to a number.
  • return type: double.
    • Returns 1.0 if n resolves to a positive number.
    • Returns -1.0 if n resolves to a negative number.
    • Returns 0.0 if n resolves to zero.
    • Returns a NULL value in the following cases:
      • n resolves to a NULL value
      • n does not resolve to a number
    • Returns NaN if n resolves to NaN.
Example:
SELECT sign(n) FROM PHtable
Value of n Output
1.89 1.0
-1.89 -1.0
0 0.0
sin(3*pi()/2) -1.0