MySQL查詢與範圍

Question

我試圖簡化一組查詢到一個單一的一個掙扎與它。

我想收集不同範圍的數，現在我這樣做的權利：

select count(*) from items where value < 0 and id = 43; 

select count(*) from items where (value >= 0 AND value <= 10) and id = 43; 

select count(*) from items where (value > 10 AND value <= 20) and id = 43; 

select count(*) from items where (value > 20 AND value <= 30) and id = 43; 

select count(*) from items where value > 30 and id = 43; 

我希望能夠做到這一點在一個單一的查詢。我怎麼能做到這一點？

此外我需要每個個人查詢仍然計數，而不僅僅是他們在一起。

Answer 1

SELECT 
    SUM(IF(value < 0, 1, 0)), 
    SUM(IF(value BETWEEN 0 AND 10, 1, 0)), 
    SUM(IF(value BETWEEN 10 AND 20, 1, 0)), 
    SUM(IF(value BETWEEN 20 AND 30, 1, 0)), 
    SUM(IF(value > 30, 1, 0)) 
FROM items 
WHERE id = 43; 

試試這個

Answer 2

也許是這樣的：

SELECT 
    SUM(CASE WHEN value < 0 and id = 43 THEN 1 ELSE 0 END) AS c1 
    SUM(CASE WHEN (value >= 0 AND value <= 10) and id = 43 THEN 1 ELSE 0 END) AS c2, 
    SUM(CASE WHEN (value > 10 AND value <= 20) and id = 43 THEN 1 ELSE 0 END) AS c3, 
    SUM(CASE WHEN (value > 20 AND value <= 30) and id = 43 THEN 1 ELSE 0 END) AS c4, 
    SUM(CASE WHEN value > 30 and id = 43 THEN 1 ELSE 0 END) AS c5 
FROM 
    items