我正在尝试计算某个时期内一匹雄性赛马(雄性)的所有后代所赢得的金额。由父亲列出,赢得最多的钱。我运行查询并遇到一个问题后得到结果Im,我无法显示父亲姓名,仅显示其ID。
SELECT `horses`.`SireID` AS `SireID` , `horses`.`HorseName` AS `Sire Name`,
COUNT( `runs`.`HorsesID` ) AS `Runs` ,
COUNT(
CASE WHEN `runs`.`Finish` =1
THEN 1
ELSE NULL
END ) AS `Wins` ,
CONCAT( FORMAT( (
COUNT(
CASE WHEN `runs`.`Finish` =1
THEN 1
ELSE NULL
END ) / COUNT
( `runs`.`TrainersID` ) ) *100, 0 ) , '%'
) AS `Percent` ,
FORMAT( SUM( `runs`.`StakeWon` ) , 0 ) AS `Stakes`
FROM runs
INNER JOIN horses ON runs.HorsesID = horses.HorsesID
INNER JOIN races ON runs.RacesID = races.RacesID
WHERE `races`.`RaceDate` >= STR_TO_DATE( '2012,07,01', '%Y,%m,%d' )
AND `races`.`RaceDate` < STR_TO_DATE( '2012,07,01', '%Y,%m,%d' ) + INTERVAL 1
MONTH
AND `horses`.`SireID` <> `horses`.`HorsesID`
GROUP BY `horses`.`SireID`, `horses`.`HorseName`
ORDER BY SUM( `runs`.`StakeWon` ) DESC
例如,在马表中进行记录,一匹马有一个horsesID,而他们也有一个sireID(他们的父亲)。 sireID在同一表的另一条记录中具有等效的horsesID,因为它也是一匹马
基本上我需要将horseName映射到sireID。
我以为自我加入会奏效。
`AND `horses`.`SireID` <> `horses`.`HorsesID``
但是它没有返回与SireID相对应的正确Sire名称。
您可以在表本身上进行JOIN。这是一个更简单的示例:
SELECT Horses.HorseID, Horses.HorseName, Horses.SireID, b.HorseName as SireName
FROM Horses
LEFT JOIN Horses b ON (Horses.SireID = b.HorseID)
您可能可以从这里弄清楚如何添加条件。
join horses sires on sires.HorsesID = horses.SireID