mysql - 两个 LIKE 条件，但先从一个检索，然后从另一个检索

Question

   SELECT *
   FROM address 
   WHERE name LIKE 'a%' OR name LIKE '% a%' LIMIT 10

此查询检索以开头 或中间单词 开头name的 s 。我怎样才能从第一个检索结果 呢？a'a%'
'% a%'LIKE 'a%'
LIKE '% a%'

Answer 1

添加ORDER BY子句，

SELECT *
FROM address
WHERE name LIKE 'a%' OR name LIKE '% a%' 
ORDER BY CASE WHEN name LIKE 'a%' THEN 0 ELSE 1 END
LIMIT 10

Answer 2

这里是：

SELECT t1.*
FROM (
   SELECT *
   FROM address 
   WHERE name LIKE 'a%'
   LIMIT 10
) t1
WHERE t1.name LIKE '% a%' 

Answer 3

一种方法是在查询中添加 ORDER BY 子句：

ORDER BY IF(name LIKE 'a%',1,2) 

---

像这样的东西：

SELECT *
  FROM address 
 WHERE name LIKE 'a%' OR name LIKE '% a%'
 ORDER BY IF(name LIKE 'a%',1,2) 
 LIMIT 10

---

为了避免对大型集合（即地址中的大量行）进行“使用文件排序”操作，并且如果您只想返回 10 行，通过限制要排序的行数，看起来更复杂的查询可能会执行得更好：

SELECT c.* 
  FROM ( SELECT a.*
           FROM (
                  SELECT *
                    FROM address 
                   WHERE name LIKE 'a%'
                   LIMIT 10 
                ) a
          UNION ALL
         SELECT b.*
           FROM address b
          WHERE b.name LIKE '% a%' AND b.name NOT LIKE 'a%'
          LIMIT 10
       ) c
 ORDER BY c.name LIKE 'a%' DESC
 LIMIT 10

Answer 4

联合查询在这里可能是有序的。根据 MySQL 文档

要使 UNION 结果中的行由每个 SELECT 一个接一个地检索到的行集组成，请在每个 SELECT 中选择一个附加列以用作排序列，并在最后一个 SELECT 之后添加一个 ORDER BY：

(SELECT 1 AS sort_col, col1a, col1b, ... FROM t1)
UNION
(SELECT 2, col2a, col2b, ... FROM t2) ORDER BY sort_col;

因此，对于您的情况，例如

(Select *, 1 as sortcol from addresses where name like 'a%')
 Union
 (Select *, 2 as sortcol from addresses where name like '% a%')
 Order by sortcol

链接：http ://dev.mysql.com/doc/refman/5.0/en/union.html