從限制和刪除的2列中獲取結果

Question

SELECT * 
FROM VB_Names 
WHERE Buurt = 'Spangen' 
    AND Gender = 'M' 
    AND Gender = 'V' 
GROUP BY Name 
ORDER BY COUNT DESC LIMIT 6 

我希望從列'性別'M'獲得3個結果，並通過計數在DESC上獲得來自列'性別'V'的列的3個結果。

Answer 1

性別在同一行中不能同時爲'M'和'V'，因此此查詢不會返回任何內容。相反，使用union all：

(SELECT * 
FROM VB_Names 
WHERE Buurt = 'Spangen' AND Gender = 'M' 
ORDER BY count DESC 
LIMIT 3 
) UNION ALL 
(SELECT * 
FROM VB_Names 
WHERE Buurt = 'Spangen' AND Gender = 'V' 
ORDER BY count DESC 
LIMIT 3 
) 

Answer 2

更改AND條件OR

SELECT * 
FROM VB_Names 
WHERE Buurt = 'Spangen' 
    AND (Gender = 'M' OR Gender = 'V') 
GROUP BY Name 
ORDER BY COUNT DESC LIMIT 6