Help with a SQL query joining multiple tables
First I will explain the case, I have a table tbl_game
with a structure as such. This table contains, the time where the game was started and pair playing the game
| id | time | pair_id |
-----------+--------------+ ---------------
1 | 123123123 | 1 |
2 | 123168877 | 1 |
and I have another table tbl_throws
which holds the score for each player. In case you are wondering, this a basic dice rolling game
| id | game_id | player_id | score |
-----------+--------------+---------------+---------|
| 1 | 1 | 1 | 2 |
| 2 | 1 | 2 | 5 |
| 3 | 1 | 1 | 9 |
| 4 | 1 | 2 | 11 |
| 5 | 2 | 1 | 7 |
| 6 | 2 | 2 | 6 |
Now, id
here is the throw id, not the game id. Here each player with player_id
1 and 2 has throws the dice twice and got the respective score as presented all in same game and just one time in another
Now, using these two table, I need to create a record set, that the tota开发者_JAVA技巧l score of each player in one game
| game_id | game_time | player1_total | player2_total|
|------------+-----------+---------------+--------------|
| 1 | 123123123 | 11 | 16 |
| 2 | 123168877 | 7 | 6 |
I tried lots of mumbo jumbo queries, but nothing is giving corrent result? What is the correct query for this?
Update
Since, most of the answers were bounded by a fact that, player1id and player2id had to be known or fixed.
So may be the information I am about to provide will help to clear the confusion.
there is another table, which holds the information of the player. tbl_pupil
Structure is like the following
| id | unique_id | name |
|---------+---------------+----------|
| 1 | 001 | some |
| 2 | 002 | another |
and these player are collectively called, a pair in another table tbl_pair
| id | player1 | player2 |
|---------+---------------+----------|
| 1 | 1 | 2 |
So, now
select
g.id
g.time
p1.id as player1id
p1.name as player1name
t.score as player1score
p2.id as player2id
p2.name as player2name
t.score as player2score
FROM
tbl_game g,
inner join tbl_pair as pair on g.pair_id = pair.id
inner join tbl_pupil as p1 on p1.id = pair.player1
inner join tbl_pupil as p2 on p2.id = pair.player2
inner join tbl_throw as t on g.id = t.game_id
This is my preliminary query, which brings the record set, on a way as such
| id | time | player1id | player1name | player1score | player2id | player2name | player2score |
----------------------------------------------------------------------------------------------------------------------------
| 1 | 12 | 1 | some | 5 | 2 | another | 2 |
| 1 | 12 | 1 | some | 5 | 2 | another | 5 |
| 1 | 12 | 1 | some | 9 | 2 | another | 9 |
| 1 | 12 | 1 | some | 11 | 2 | another | 11 |
Now I am just showing the results of one game id by the way. I don't save sufficient knowledge, to group the above record into one, with player1 separate sum score in one column and playe2's separate sum of score in another column.
Try this:
SELECT
tbl_game.id AS game_id,
tbl_game.time AS game_time,
SUM(CASE WHEN player_id = 1 THEN score ELSE 0 END) AS player1_total,
SUM(CASE WHEN player_id = 2 THEN score ELSE 0 END) AS player2_total
FROM tbl_game JOIN tbl_thorws ON tbl_game.id = tbl_throws.game_id
GROUP BY tbl_game.id
This is similar to some of the other answers, but crucially doesn't depend on the player IDs being 1 and 2.
select
game_id = g.id,
game_time = g.time,
player1_total = SUM(case t.player_id when p.player1_id then t.score else 0 end),
player2_total = SUM(case t.player_id when p.player2_id then t.score else 0 end)
from
tbl_game g
join tbl_throws t on g.id = t.game_id
join ( --Get the player IDs for this game
select
game_id,
player1_id = MIN(player_id),
player2_id = MAX(player_id)
from
tbl_throws
group by game_id
) p
on p.game_id = t.game_id
group by
g.id, g.time
Just for fun I've generalized the above out to allow more > 2 players:
The 2 CTE tables just show the test data I'm using
;WITH tbl_game as (
select ID = 1, time = 123123123, pair_id = 1
union select ID = 2, time = 123168877, pair_id = 1
),
tbl_throws as (
select id = 1, game_id = 1, player_id = 1, score = 2
union select id = 2, game_id = 1, player_id = 2, score = 5
union select id = 2, game_id = 1, player_id = 3, score = 5
union select id = 3, game_id = 1, player_id = 1, score = 9
union select id = 4, game_id = 1, player_id = 2, score = 11
union select id = 5, game_id = 2, player_id = 1, score = 7
union select id = 6, game_id = 2, player_id = 2, score = 6
)
select
game_id = g.id,
game_time = g.time,
player1_id = MAX(case x.player_no when 1 then t.player_id else 0 end),
player1_total = SUM(case x.player_no when 1 then t.score else 0 end),
player1_id = MAX(case x.player_no when 2 then t.player_id else 0 end),
player2_total = SUM(case x.player_no when 2 then t.score else 0 end),
player3_id = MAX(case x.player_no when 3 then t.player_id else 0 end),
player3_total = SUM(case x.player_no when 3 then t.score else 0 end),
player4_id = MAX(case x.player_no when 4 then t.player_id else 0 end),
player4_total = SUM(case x.player_no when 4 then t.score else 0 end)
/* Add more rows for the number of players permitted in a single game */
from
tbl_game g
join tbl_throws t on g.id = t.game_id
cross apply (
select player_no = COUNT(distinct player_id)
from tbl_throws sub
where sub.player_id <= t.player_id
and Sub.game_id = t.game_id
) x
group by
g.id, g.time
You need to inner join the two tables, and aggregate your scores. To do the basic pivot you are after I used a CASE
statement to aggregate by player.
SELECT G.Id as Game_Id,
G.time as Game_Time,
SUM(CASE WHEN t.Player_id = 1 THEN t.score ELSE 0 END) as Player1_total,
SUM(CASE WHEN t.Player_id = 2 THEN t.score ELSE 0 END) as Player2_total
FROM tbl_game G
INNER JOIN tbl_throws T
ON g.id = t.game_id
GROUP BY g.ID, g.time
I think this should do pretty much what you want to do.
SELECT
tbl_game.id as game_id,
tbl_game.time as game_time,
SUM(player1.score) as player1_total,
SUM(player2.score) as player2_total
FROM tbl_game
INNER JOIN tbl_throws player1 ON player1.game_id = tbl_game.id AND player1.player_id = 1
INNER JOIN tbl_throws player2 ON player2.game_id = tbl_game.id AND player2.player_id = 2
GROUP BY tbl_game.id, tbl_game.time
SELECT t.game_id
, t.game_time
, ( SELECT SUM(t.score)
FROM tbl_throws AS t
WHERE t.game_id = g.id
AND player_id = 1
) AS player1_total
, ( SELECT SUM(t.score)
FROM tbl_throws AS t
WHERE t.game_id = g.id
AND player_id = 2
) AS player2_total
FROM tbl_game AS g
精彩评论