同一行中提取MIN和MAX

Question

試想一個表稱爲training_route其中包含幾個行，每行有一個rowId，gpsLocation和athleteId並考慮以下因素：

• 最低rowId定義了第一的位置和最大rowId定義的最後位置
• 所有行一起定義了相關運動員的路線運行

例。

rowId athleteId gpsLocation 
100  1   "40.7127837,-74.00594130000002" <- first location for athlete #1 
101  1   "41.1234872,-71.41300000022342" 
102  1   "42.1234872,-69.23112200022342" <- last location for athlete #1 
103  2   "39.5993499,-74.00594130000002" <- first location for athlete #2 
104  2   "38.9093885,-73.31300000022342" 
106  2   "37.1234872,-63.34215200022342" <- last location for athlete #2 
107  3   ... 

我想什麼有是由非常相同的查詢由athleteId分組，同樣的行中的每個路徑的第一個和最後的位置：

athleteId firstLocation      lastLocation 
1   "40.7127837,-74.00594130000002"  "42.1234872,-69.23112200022342" 
2   "39.5993499,-74.00594130000002"  "37.1234872,-63.34215200022342" 
3   ...    ... 

如何將這項MySQL-查詢看起來像？

P.S.

我已經試過這樣的事情：

SELECT training_route.athleteId, 
     (SELECT training_route.gpsLocation FROM training_route WHERE training_route.athleteId = route.athleteId ORDER BY training_route.rowId ASC LIMIT 1) AS firstLocation, 
     (SELECT training_route.gpsLocation FROM training_route WHERE training_route.athleteId = route.athleteId ORDER BY training_route.rowId DESC LIMIT 1) AS lastLocation, 
FROM training_route AS route 
WHERE training_route.athleteId IN (1, 2, 3) GROUP BY training_route.athleteId; 

但我很慚愧，是我想出來的，到目前爲止，因爲它是完全不可接受的性能比較明智的最好的。

Answer 1

下面應該使用MySQL

SELECT * 
FROM (
     SELECT MIN(rowid) minrowid 
       , MAX(rowid) maxrowid 
       , athleteid 
     FROM training_route 
     GROUP BY 
       athleteid 
     ) minmax 
     INNER JOIN training_route trmin ON trmin.athleteid = minmax.athleteid 
              AND trmin.minrowid = minmax.rowid 
     INNER JOIN training_route trmax ON trmax.athleteid = minmax.athleteid 
              AND trmax.maxrowid = minmax.rowid 

的想法是

• 得到最小和最大的rowid的每個運動員
• 與表再次加入之前的結果得到gpscoörodinatesmin min rowid
• 並再次與原始表加入以獲取gpscoörodi納茨爲最大的rowid