将两个 mysql 查询合并为一个

组合这两个查询的正确语法是什么？

SELECT clicks FROM clicksTable WHERE clicks > 199 ORDER BY clicks ASC LIMIT 1

and

SELECT clicks FROM clicksTable ORDER BY clicks DESC LIMIT 1

I tried:

SELECT clicks FROM clicksTable WHERE clicks > 199 ORDER BY clicks ASC LIMIT 1
UNION
SELECT clicks FROM clicksTable ORDER BY clicks DESC LIMIT 1;

但我得到“UNION 和 ORDER BY 的错误使用”。

EDIT此外，我希望结果在一行中返回。这样我就可以访问 php 中的值，例如

$row['nextclick'] and $row['topclick'] 

根据西蒙的建议，我不应该使用 UNION 因为我想返回单行数据

你不能ORDER BY在你的第一个SELECT进而UNION it.

Edit
不过你可以

将 ORDER BY 或 LIMIT 应用于单个 SELECT，将子句放在包含 SELECT 的括号内：

如在MySQL UNION 文档 http://dev.mysql.com/doc/refman/5.1/en/union.html

(SELECT a FROM t1 WHERE a=10 AND B=1 ORDER BY a LIMIT 10)
UNION
(SELECT a FROM t2 WHERE a=11 AND B=2 ORDER BY a LIMIT 10);

这使得你的 SQL

(SELECT clicks FROM clicksTable WHERE clicks > 199 ORDER BY clicks ASC LIMIT 1)
UNION
(SELECT clicks FROM clicksTable ORDER BY clicks DESC LIMIT 1);

Edit 2
返回array

SELECT (SELECT clicks 
        FROM clicksTable 
        WHERE clicks > 199 
        ORDER BY clicks ASC 
        LIMIT 1) AS NextClick,
       (SELECT clicks 
        FROM clicksTable 
        ORDER BY clicks DESC 
        LIMIT 1) AS TopClick;