MySQL SIGN function is one of the Numeric Functions, which is to return the sign of the specified expression. And the return value is either Positive (+1), Negative (-1), or Zero (0). The basic syntax of the SIGN in MySQL is as shown below:
SELECT SIGN (Numeric_Expression) FROM Source
- If the Expression is Zero, the SIGN function returns Zero as a result.
- If the Numeric_Expression is Negative Number, it returns Negative One(-1) as a result.
- And If the Expression is positive Number, the SIGN function returns Positive One(+1).
To demonstrate this MySQL SIGN Numeric function, we are going to use the below shown data

MySQL SIGN Function Example 1
The MySQL SIGN finds and returns the sign of a specified value. The following query shows multiple ways to use the SIGN function.
-- MySQL SIGN Function Example -- Finding Sign for Negative Value SELECT SIGN(-240.75) AS `Sign Value`; -- Finding Sign for Positive Value SELECT SIGN(125.267) AS `Sign Value`; -- Finding Sign for Zero SELECT SIGN(0) AS `Sign Value`; -- Sign of string value SELECT SIGN('125.274') AS `Sign Value`; -- Sign Example on String SELECT SIGN('MySQL') AS `Sign Value`; -- Sign Example on NULLs SELECT SIGN('NULL') AS `Sign Value`;
From the screenshot below, you can see that we used SIGN function on different values.

and

MySQL SIGN Example 2
The MySQL SIGN Numeric also allows you to check the sign value for the column data. In this example, we are going to find the sign value for all the records present in the Service Grade column.
-- MySQL SIGN Function Example USE mysqltutorial; SELECT Product, Color, StandardCost, Sales, TaxAmt, ServiceGrade, SIGN(ServiceGrade) AS `Grade Sign` FROM `numeric functions`;
