擊球平均MySQL查詢

Question

您可能需要一些板球知識來幫助解決這個問題。鑑於下表，這個查詢會產生這個結果嗎？

Table: batsmen 
batsmanname | runsscored | howout 
Colin  | 10   | bowled 
Colin  | 20   | caught 
Steve  | 10   | bowled 
Steve  | 20   | not out 

SELECT batsmanname, SUM(runsscored)/COUNT(howout) AS battingavg 
FROM batsmen 
WHERE howout <> 'not out' 
GROUP BY batsmananme 

Result: 
batsmanname | battingavg 
Colin  | 15 
Steve  | 30 

Answer 1

這將產生你想要的結果：

SELECT b1.name, SUM(b1.runsscored)/b2.NumOut as bat_avg 
FROM batsmen b1 
INNER JOIN 
(
    select name, COUNT(howout) as NumOut 
    from batsmen 
    WHERE howout <> 'not out' 
    GROUP BY name 
) b2 
    ON b1.name = b2.name 
GROUP BY b1.name 

見SQL Fiddle with demo