Question

面对这样的问题 - 我无法将这两个请求结合起来，怎么样？来自一个表的所有数据

SELECT
  max(f.price) AS max_rent,
  min(f.price) AS min_rent
FROM Commercial f
WHERE f.type = 1;
SELECT
  max(f.price) AS max_sale,
  min(f.price) AS min_sale
FROM Commercial f
WHERE f.type = 0;

收到结果。 2个结果表

+---------+---------+ +---------+---------+
| max_sale| min_sale| |max_sale | min_sale|
+---------+---------+ +---------+---------+
|  23     |  45     | |   15    |  52     | 
+---------+---------+ +---------+---------+

预期结果。 1表结果

+---------+---------+---------+---------+
| max_sale| min_sale| max_sale| min_sale|
+---------+---------+---------+---------+
|  23     |  45     |   15    |  52     | 
+---------+---------+---------+---------+

Answer 1

如何使用group by？

SELECT f.type,
       max(f.price) AS max_price_for_sale,
       min(f.price) AS min_price_for_sale
FROM Commercial f
WHERE f.type IN (0, 1)
GROUP BY f.type;

Answer 2

只需在中间添加联合

SELECT
  max(f.price) AS max_price_for_rent,
  min(f.price) AS min_price_for_rent
FROM Commercial f
WHERE f.type = 1;

UNION 

SELECT
  max(f.price) AS max_price_for_sale,
  min(f.price) AS min_price_for_sale
FROM Commercial f
WHERE f.type = 0;

如果您想保留重复项，请添加UNION ALL

但是，对于此特定查询，使用GROUP BY和Gordon Linoff的答案会更好。

Answer 3

这对你有用吗？它应该沿着一行返回4列：

SELECT
    C1.max_rent,
    C1.min_rent,
    C0.max_rent,
    C0.min_rent
FROM
    (
    SELECT
        max(f.price) AS max_rent,
        min(f.price) AS min_rent
    FROM Commercial f
    WHERE f.type = 1) C1,
    (
    SELECT
        max(f.price) AS max_rent,
        min(f.price) AS min_rent
    FROM Commercial f
    WHERE f.type = 0) C0

如何将2个查询组合到单个表的sql中的一个查询数据库中？

3 个答案: