SQL顯示信息

Question

該查詢目前顯示MAX（海拉）到目前爲止

SELECT max(hella) 
FROM (
SELECT G.firstname, G.lastname, count(*) as hella 
FROM guest G, Timeslot TS, shows H 
where G.timeslotnum = TS.timeslotnum 
AND TS.shownumber = H.shownumber 
AND H.showname = 'Fitness' 
Group by g.firstname, G.lastname 
ORDER by hella 
) 
As blabla 

我想展示最大的名字和姓氏（海拉）項

Answer 1

這很像@maniek或@zfus已發佈的內容：返回單行，如果有關係，則返回任意選擇。 但適當的JOIN語法和更短一些語法糖：

SELECT g.firstname, g.lastname, count(*) AS hella 
FROM guest g 
JOIN timeslot t USING (timeslotnum) 
JOIN shows s USING (shownumber) 
WHERE s.showname = 'Fitness' 
GROUP BY 1,2 
ORDER BY 3 DESC 
LIMIT 1; 

SQL Fiddle（重用@sgeddes'小提琴）。

Answer 2

試試這個...

WITH CTE as 
(
SELECT G.firstname, G.lastname, count(*) as hella 
FROM guest G, Timeslot TS, shows H 
where G.timeslotnum = TS.timeslotnum 
AND TS.shownumber = H.shownumber 
AND H.showname = 'Fitness' 
Group by g.firstname, G.lastname 
) 
SELECT firstname, lastname, hella 
FROM CTE A 
WHERE hella= (SELECT MAX(HELLA) FROM CTE B 
WHERE A.firstname=B.firstname 
and A.lastname=B.lastname) 
As blabla 

Answer 3

我不是100％肯定我明白你的問題，但假設你正在尋找最記錄計數的人的姓和名，這樣的事情應該工作：

with cte as (
    select g.firstname, g.lastname, count(*) cnt 
    from guest g 
     join timeslot ts on g.timeslotnum = ts.timeslotnum 
     join shows s on ts.shownumber = s.shownumber and s.showname = 'Fitness' 
    group by g.firstname, g.lastname 
) 
select firstname, lastname 
from cte 
where cnt = (select max(cnt) from cte); 

• SQL Fiddle Demo

Answer 4

SELECT G.firstname, G.lastname, count(*) as hella 
FROM guest G, Timeslot TS, shows H 
where G.timeslotnum = TS.timeslotnum 
AND TS.shownumber = H.shownumber 
AND H.showname = 'Fitness' 
Group by g.firstname, G.lastname 
ORDER by hella desc 
limit 1 

Answer 5

雖然SoulTrain和sgeddes有從一個角度回答，如果你的願望是，以示與最大計數只有一條記錄，你可以簡單地寫這樣的事情：

SELECT G.firstname, G.lastname, count(*) as hella 
FROM 
    guest G, 
    Timeslot TS, 
    shows H 
where 
    G.timeslotnum = TS.timeslotnum 
    AND TS.shownumber = H.shownumber 
    AND H.showname = 'Fitness' 
Group by 
    g.firstname, 
    G.lastname 
ORDER by 
    hella desc 
fetch first 1 rows only 

Example in SQLFiddle