MySQL查询与范围

Question

我试图简化一组查询到一个单一的一个挣扎与它。

我想收集不同范围的数，现在我这样做的权利：

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; 

我希望能够做到这一点在一个单一的查询。我怎么能做到这一点？

此外我需要每个个人查询仍然计数，而不仅仅是他们在一起。

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; 

试试这个

Answer 2

也许是这样的：

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