php - 你如何在 MySQL 中订购 UNION？

Question

我想知道，我们如何在基于联合的 mysql_query 中对列表 (DESC) 进行排序，当我们在 PHP/MYSQL 中获取此查询时，我们会得到输出。但我们只是简单地在此查询中输入顺序。

 (SELECT info.id 
 FROM info, 1_all 
 WHERE 1_all.id = info.id and 1_all.table_type = 'disp'  AND 1_all.year = '$year' AND  info.category IN (1,2,3) AND info.area IN (2,5,6)  
 GROUP BY resinfo.id ) 
UNION ALL 
 (SELECT info.id 
 FROM info, 2_all 
 WHERE 2_all.id = info.id and 2_all.table_type = 'disp' AND 2_all.year = '$year' AND info.category IN (1,2,3) AND info.area IN (2,5,6) 
 GROUP BY info.id)

Answer 1

To use an ORDER BY or LIMIT clause to sort or limit the entire UNION result, parenthesize the individual SELECT statements and place the ORDER BY or LIMIT after the last one. The following example uses both clauses:

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

http://dev.mysql.com/doc/refman/5.5/en/union.html