MAX

Return the maximum value for an expression (numeric, character, or datetime).
MAX(expression)
Note: The input expression for a MAX function cannot be a Boolean data type.
The following example returns the closing matchday for each season.
premdb=# SELECT seasonid, MAX(matchday) 
FROM match WHERE matchday IS NOT NULL 
GROUP BY seasonid ORDER BY seasonid;
 seasonid |         max         
----------+---------------------
        2 | 1994-05-08 00:00:00
        3 | 1995-05-14 00:00:00
        4 | 1996-05-04 00:00:00
        5 | 1997-05-11 00:00:00
        6 | 1998-05-10 00:00:00
        7 | 1999-05-16 00:00:00
        8 | 2000-05-14 00:00:00
        9 | 2001-05-19 00:00:00
       10 | 2002-05-11 00:00:00
...
The following example returns the "maximum" nickname value from the team table:
premdb=# SELECT MAX(nickname) FROM team;
  max   
--------
 Wolves
(1 row)

The following example returns the most goals scored in a single game per season. The MAX function is applied to substrings of the ftscore column (full-time score). The first substring returns the goals scored by the home team, and the second the goals scored by the away team.

premdb=# SELECT seasonid, 
MAX(SUBSTR(ftscore,1,1)::SMALLINT + SUBSTR(ftscore,3,3)::SMALLINT) AS maxgoals_per_match 
FROM matchcopy GROUP BY seasonid ORDER BY 1;
 seasonid | maxgoals_per_match 
----------+--------------------
        1 |                  8
        2 |                  9
        3 |                  9
        4 |                  8
        5 |                  9
        6 |                  9
        7 |                  9
        8 |                  9
        9 |                  8
       10 |                  8
       11 |                  8
       12 |                  8
       13 |                  9
       14 |                  7
       15 |                  8
       16 |                 11
       17 |                  8
       18 |                 10
       19 |                  8
       20 |                 10
       21 |                 10
       22 |                  9
...

MIN and MAX with NaN Values

Yellowbrick supports NaN (not a number) as a floating-point value. When MIN and MAX functions are applied to data that contains NaN values, NaN is returned as the maximum value. NaN sorts as greater than all other floating-point values, including +inf (infinity).