In sql, MAX() function returns the maximum value of the columns having numeric value.

Syntax for MAX()

SELECT MAX(column_name)
FROM table_name
WHERE condition;

Now, let' see how to return maximum values in a column using python

Before that make sure that you have created a database named - tutorialsinhand  and table inside it  market with the following records.

Steps:

1. Import mysql.connector module
    Syntax:
    import mysql.connector

2. Create the connection object to connect with xampp server using the below credentials.
    Syntax:
    connection_obj = mysql.connector.connect(
                          host="localhost",
                          user="root",
                          password=""
                                                                        )
3. Create cursor object to execute the query.
    Syntax:
    connection_obj.cursor()

4. Write sql query to select columns by applying MAX aggregate function on a column.
   
5. Fetch the resulted rows using fetchall().
    Syntax:
    cursor.fetchall()

6. Display using for loop 
     Syntax:
         for i in results:
            print(i)

Note - It will return the values in a tuple.

Example:

In this example, we will return maximum value in ratings column.

#import the module
import mysql.connector

#create the connection by specifying the 
#hostname-localhost
#username-root
#password-''(empty) and
#database is tutorialsinhand
connection_obj = mysql.connector.connect(
  host="localhost",
  user="root",
  password="",
  database="tutorialsinhand"
)

#creating cursor object
cursor_obj = connection_obj.cursor()


#return maximum from rating column
cursor_obj.execute("SELECT MAX(rating) FROM market")

#fetch the rows
results = cursor_obj.fetchall()

#get the values
for i in results:
  print("Maximum rating: ",i[0])

Output:

Maximum rating:  8

We can see that maximum  rating is 8.

In Sql, GROUP BY statement is mostly used along with the aggregate functions to group the result based on one or multiple columns.

MAX() with GROUP BY will return maximum values in a group.

Syntax of GROUP BY

SELECT MAX(column_name)
FROM table_name
GROUP BY column_name;

Important points

• We can specify multiple columns in GROUP BY.
• We can use more than one aggregate function for grouping the result-set.
• If ORDER BY is used then it should only be used after GROUP BY.

Example: In this example, we are grouping rating with market_area column, so it will group the values in market_area column and return maximum value  in each group.

#import the module
import mysql.connector

#create the connection by specifying the 
#hostname-localhost
#username-root
#password-''(empty) and
#database is tutorialsinhand
connection_obj = mysql.connector.connect(
  host="localhost",
  user="root",
  password="",
  database="tutorialsinhand"
)

#creating cursor object
cursor_obj = connection_obj.cursor()


#return Maximum from rating column by grouping market_area column
cursor_obj.execute("SELECT market_area,MAX(rating) FROM market GROUP BY market_area")

#fetch the rows
results = cursor_obj.fetchall()

#get the values
for i in results:
  print("Market Area: ",i[0]," & ", "Maximum-Rating: ",i[1])
  print()