SQL MAX Function
SQL > SQL Functions >
The MAX function is used to find the maximum value in an expression.
The syntax for the MAX function is,
SELECT MAX (<expression>)
<expression> can be a column name or an arithmetic operation. An arithmetic operation can include more than one column, such as ("column1" + "column2").
It is also possible to have one or more columns in addition to the MAX function in the SELECT statement. In those cases, these columns need to be part of the GROUP BY clause as well:
SELECT "column_name1", "column_name2", ... "column_nameN", MAX (<expression>)
GROUP BY "column_name1", "column_name2", ... "column_nameN";
We use the following table for our examples.
Example 1: MAX function on a column
To find the maximum sales amount, we type in,
SELECT MAX(Sales) FROM Store_Information;
1500 represents the maximum value of all Sales entries: 1500, 250, 300, and 700.
Example 2: MAX function on an arithmetic operation
Assume that sales tax is 10% of the sales amount, we use the following SQL statement to get the maximum sales tax amount:
SELECT MAX(Sales*0.1) FROM Store_Information;
SQL will first calculate "Sales*0.1" and then apply the MAX function to the result for the final answer.
Example 3: MAX function with a GROUP BY clause
To get the maximum sales amount for each store, we type in,
SELECT Store_Name, MAX(Sales) FROM Store_Information GROUP BY Store_Name;