将两个mysql查询合并为一个

Question

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

和

SELECT clicks FROM clicksTable ORDER BY clicks DESC LIMIT 1

我试过了:

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的使用不正确".

编辑 此外,我希望结果返回一行.这样我就可以访问php中的值了

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

根据Simon的建议,我不应该使用UNION,因为我想返回一行数据

Answer 1

你不能ORDER BY在你的第一个SELECT然后UNION它.

编辑
但是你可以

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

与MySQL UNION文档中一样

(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);

然后,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);

编辑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;