[英]select distinct from table mysql
I cant filter in a good way my table, this is my table: 我不能很好地过滤我的桌子,这是我的桌子:
+----------+-----------+-------+------+
| PersonID | FirstName | Level | Time |
+----------+-----------+-------+------+
| 1 | Beru | 51 | 22 |
| 2 | Pepe | 42 | 13 |
| 3 | Tom | 30 | 15 |
| 4 | Beru | 51 | 32 |
| 5 | Tom | 28 | 15 |
| .... | ... | .... | ... |
+----------+-----------+-------+------+
........................... more players
I want to order it by Bigger Level and Time, but not repeating FirstName and only 5 first, its posible? 我想按更大的级别和时间订购它,但不重复名字,只重复5个,这可能吗? thanks.
谢谢。
So my Output Should be some stuff like this: 所以我的输出应该是这样的:
- FirstName - Level - Time
- Beru - 51 - 32
- Pepe - 42 - 13
- Tom - 30 - 15
- .... more players...
I hope someone can help me. 我希望有一个人可以帮助我。 I know what to use, but i dont know how to use it.
我知道该怎么用,但我不知道该怎么用。
SELECT o.FirstName, o.Level, o.Time
FROM myTable o
GROUP BY FirstName
ORDER BY o.Level*100+o.Time DESC
LIMIT 0,10
thanks everyone, obviusly that mysql script doesnt work, i hope you know how to do it, :) 谢谢大家,很明显,mysql脚本无法正常工作,我希望您知道该怎么做,:)
You can use variables in order to get the greatest-per-player record: 您可以使用变量以获得最高的每人记录:
SELECT PersonID, FirstName, Level, Time
FROM (
SELECT PersonID, FirstName, Level, Time,
@rn := IF(@name = FirstName, @rn + 1,
IF(@name := FirstName, 1, 1)) AS rn
FROM mytable
CROSS JOIN (SELECT @rn := 0, @name := '') AS vars
ORDER BY FirstName, Level DESC, Time DESC) AS t
WHERE rn = 1
ORDER BY FirstName LIMIT 0, 5
This can be done with a fiddle using GROUP_CONCAT:- 这可以通过使用GROUP_CONCAT来完成:
SELECT FirstName,
SUBSTRING_INDEX(GROUP_CONCAT(Level ORDER BY Level DESC, Time DESC), ',', 1) AS Level,
SUBSTRING_INDEX(GROUP_CONCAT(Time ORDER BY Level DESC, Time DESC), ',', 1) AS Time
FROM myTable
GROUP BY FirstName
To order that in the right order:- 以正确的顺序订购:-
SELECT FirstName,
SUBSTRING_INDEX(GROUP_CONCAT(Level ORDER BY Level DESC, Time DESC), ',', 1) AS Level,
SUBSTRING_INDEX(GROUP_CONCAT(`Time` ORDER BY Level DESC, Time DESC), ',', 1) AS `Time`
FROM myTable
GROUP BY FirstName
ORDER BY Level*100+`Time` DESC
LIMIT 10
SQL fiddle for it here:- SQL在这里摆弄:-
http://www.sqlfiddle.com/#!9/03457/1 http://www.sqlfiddle.com/#!9/03457/1
Note that this ordering won't be that efficient (no way to use indexes). 请注意,这种排序方式效率不高(无法使用索引)。
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