SIGN (SQL)

A numeric function that returns the sign of a given numeric expression.

Synopsis

SIGN(numeric-expression)

{fn SIGN(numeric-expression)}

Description

SIGN returns the following:

-1 if numeric-expression is less than zero.
0 (zero) if numeric-expression is zero: 0, +0, or -0.
1 if numeric-expression is greater than zero.
NULL if numeric-expression is NULL, or if it is a non-numeric string.

SIGN can be used as either an ODBC scalar function (with the curly brace syntax) or as an SQL general function.

SIGN converts numeric-expression to canonical form before determining its value. For example, SIGN(-+-+3) and SIGN(-3+5) both return 1, indicating a positive number.

Note:

In InterSystems SQL, two negative signs (hyphens) are the in-line comment indicator. For this reason, a SIGN argument specifying two successive negative signs must be presented as a numeric string enclosed in quotes.

Arguments

numeric-expression

A number for which the sign is to be returned.

Examples

The following examples shows the effects of SIGN:

SELECT SIGN(-49) AS PosNeg

returns -1.

SELECT {fn SIGN(-0.0)} AS PosNeg

returns 0.

SELECT SIGN(-+-16.748) AS PosNeg

returns 1.

SELECT {fn SIGN(NULL)} AS PosNeg

returns <null>.