This article will discuss how we can use the max() function in Standard SQL. Keep in mind that various database engines may provide variations of this function.

## What is SQL Max() function?

The max() function in SQL is an aggregate function. It takes a numerical set and returns the largest value from the provided set. You can pass a column containing numerical values or an expression that returns a numerical value(s).

Since the function returns a single value, we can think of it as a scalar function.

The function syntax is shown below:

expression

)

[OVER (...)]

The function takes one argument containing non-null numeric values. Therefore, the argument must have numeric values.

The function will return a similar data type as the provided input values.

## Example Usage

The following are sample examples of using the max() function in SQL.

**Example 1
**A simple example of usage of the max() function is shown below:

MAX(nums) AS MAX

FROM

UNNEST([100,23,45,12,192,344,32,56,76]) AS nums;

The example above uses the max function to get the largest number in an array of numerical values. The return value is:

344

**Example 2
**Although it is recommended to pass numeric values as the parameter of the function, it can work with non-numeric values, as shown in the example below:

MAX(str) AS MAX

FROM

UNNEST(['a','b','c', 'hello']) AS str;

In this example, the function will compare the number of characters in each string value. The resulting value is as shown:

hello

**Example 3
**We can also calculate the max value in a column. For example, suppose we have a table containing payment details, as shown in the example below:

We can calculate the maximum amount using the max function as shown below:

MAX

-------

4.99

(1 ROW)

The above returns the highest amount from the column.

## Conclusion

This article discussed the SQL max() function in Standard SQL. Using this function, you can determine the maximum value within a provided set.