# SIGN

The SQL SIGN function is a mathematical function that is used to determine the sign of a numeric expression. The function returns a value of -1, 0, or 1, depending on whether the input expression is negative, zero, or positive, respectively.

## Syntax

The syntax of the SIGN function is as follows:

```SIGN(numeric_expression)
```

Here, numeric_expression is the expression whose sign needs to be determined.

The SIGN function can be used with any numeric data type such as INT, BIGINT, FLOAT, DECIMAL, etc.

### Example

Let’s consider an example to better understand the usage of the SIGN function:

```SELECT SIGN(-10) AS result;
```

In this example, the SIGN function is applied to the numeric value -10. Since the value is negative, the function returns -1 as the result. Therefore, the output of the above SQL statement would be: -1.

Similarly, we can apply the SIGN function to positive and zero values as well:

```SELECT SIGN(20) AS result;
```

In this case, the value 20 is positive, so the function returns 1 as the result: 1.

```SELECT SIGN(0) AS result;
```

In this case, the value 0 is neither positive nor negative, so the function returns 0 as the result: 0.

In conclusion, the SIGN function is a useful mathematical function in SQL that can be used to determine the sign of a numeric expression. It is particularly useful in applications where we need to distinguish between positive, negative, and zero values.