What is the SQL MAX() Function & How to Use It?

What is the SQL MAX() Function & How to Use It?

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Most interviewers in project management industries will expect you to be able to answer fundamental questions from the SQL and database. This way they’ll be able to prove your relevance in their organization.

In this article, we provide you with the best information and answers on SQL max function and the various ways it can be applied.

What is SQL MAX() Function?

SQL Max is one of the aggregate functions in the SQL language. Its primary purpose is to find the record with the maximum value among a group of data. In other words, it gives the largest value of an expression in a SELECT statement. The SQL max statement syntax is as follows:

SELECT MAX(aggregate_expression)
FROM tables
[WHERE conditions];

The above syntax is only applicable when dealing with data that doesn?t need grouping. For grouped data, there is a slight change as shown below:

SELECT 1st expression, 2nd expression, ? nth expression,
MAX (aggregate_epression)
FROM tables
[WHERE conditions]
GROUP BY 1st expression, 2nd expression, ? nth expression;

The parameters are broken down below to help you understand the SQL select max function.

The 1st, 2nd, and nth expressions are those that aren?t encapsulated within the SQL max function. However, they are mandatory in the GROUP BY clause at the end of the SQL statement.

The aggregate_expression refers to the record that will return the maximum value the function looks for. The ?tables? segment relates to the tables from which you would like to obtain the records. Therefore, in the FROM clause, there must be more than one tables listed. WHERE conditions, which are often optional, refer to those conditions that are mandatory for the selection of the records.

How to Use the SQL?MAX() Function

One of the simplest ways to implement the max function is to return just one field that calculates the maximum value. For instance, one may need to the maximum marks scored by the students in a particular class. The SQL select statement would be:

SELECT MAX(Marks) AS ?Highest marks?
FROM student_details;

In the above example, the MAX(Marks) field has been aliased as ?Highest marks?. Because of that, the ?Highest marks? will appear as the field name.

The second way of using the function is employing the Group by Clause. In the above example, you might want to specify the particular subject from which you want to obtain the highest marks. Therefore, the SQL select statement with the max function will become:

SELECT subject, MAX(Marks) AS ?Highest marks?
FROM student_details
GROUP BY subject;

Only one column has been listed in this SQL SELECT statement that isn?t encapsulated in the max SQL function. Therefore, it becomes mandatory to use the SQL GROUP BY clause. The ?subject? field must be listed in the ?group by? section.

Other functions of the include obtaining the maximum function on the date.We can also do this by using the SQL max date function, in the same way as outlined by the SQL max() syntax.

This article provides you with the best way to use and describe the SQL max function. After going through it, feel free to share your views about these answers in the comment section.

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