MySQL view - calculated column from multiple tables returning NULL

Question

Suppose I have a two tables. Table T1 like:

Game Player Points Assists
 1     1     10     5
 1     2     5      10

T2 like:

Game Player Fouls Turnovers
1      1     5       5
1      2     10      10

I'd like to create a view with one row per player and a new field rating, where rating is a equally weighted sum of Points, Assists, Fouls,Turnovers for each player. (i.e. rating = .25 * Points + .25 * Assists + .25 * Fouls + .25 * Turnovers)

I create the view:

CREATE VIEW `player_view` AS (
SELECT Player,
  SUM( 
  Points *0.25 +
  Assists *0.25 +
  Fouls *0.25 +
  Turnovers *0.25) AS Rating)
FROM T1 INNER JOIN T2 ON
  T1.Player = T2.Player
AND T1.Game = T2.Game
GROUP BY Player

But rather than returning a value, I get NULL for all Rating:

Player Rating
1       NULL
2       NULL

Initially, I was faced with

Expression #2 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'support_desk.mod_users_groups.group_id' which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by

So I disabled only_full_group_by via SET sql_mode='STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_ENGINE_SUBSTITUTION'

So now, although the view returns a results set, the Ratings are all NULL. Please assist.

Answer 1

Seems that you missed an operator between the column in sum eg + could be you ahve some hidden char in the key fields so.. try trim()

CREATE VIEW `player_view` AS 
SELECT Player,
  SUM( 
  t1.Points*0.25 + 
  t1.Assists*0.25  +
  t2.Fouls*0.25 + 
  t2.Turnovers*0.25) AS Rating
  )
FROM T1 
INNER JOIN T2 ON
  trim(T1.Player) = trim(T2.Player)
    AND trim(T1.Game) = trim(T2.Game);
GROUP BY Player

select * from player_view;