用于检查名称是否以元音开头和结尾的SQL查询

Question

我想查询表格中的CITY名字列表,这些名字的STATION(id, city, longitude, latitude)元音是他们的第一个和最后一个字符.结果不能包含重复项.

为此我写了一个类似于WHERE NAME LIKE 'a%'25条件的查询,每个元音都用于其他每个元音,这是非常笨拙的.有没有更好的方法呢？

Answer 1

您可以使用正则表达式:

SELECT DISTINCT city
FROM   station
WHERE  city RLIKE '^[aeiouAEIOU].*[aeiouAEIOU]$'

Answer 2

在Microsoft SQL Server中,您可以从以下查询中实现此目的:

SELECT distinct City FROM STATION WHERE City LIKE '[AEIOU]%[AEIOU]'

要么

SELECT distinct City FROM STATION WHERE City LIKE '[A,E,I,O,U]%[A,E,I,O,U]'

Answer 3

您可以为 MySQL 尝试一种简单的解决方案：

SELECT DISTINCT city FROM station WHERE city REGEXP "^[aeiou].*[aeiou]$";

Answer 4

使用正则表达式.

WHERE name REGEXP '^[aeiou].*[aeiou]$'

^并将$匹配锚定到值的开头和结尾.

在我的测试中,这不会在name列上使用索引,因此需要执行完整扫描

WHERE name LIKE 'a%a' OR name LIKE 'a%e' ...

我认为要使用一个索引,你需要使用每个测试第一个字母的查询联合.

SELECT * FROM table
WHERE name LIKE 'a%' AND name REGEXP '[aeiou]$'
UNION
SELECT * FROM table
WHERE name LIKE 'e%' AND name REGEXP '[aeiou]$'
UNION
SELECT * FROM table
WHERE name LIKE 'i%' AND name REGEXP '[aeiou]$'
UNION
SELECT * FROM table
WHERE name LIKE 'o%' AND name REGEXP '[aeiou]$'
UNION
SELECT * FROM table
WHERE name LIKE 'u%' AND name REGEXP '[aeiou]$'

Answer 5

你可以试试这个

    select city
    from station where SUBSTRING(city,1,1) in ('A','E','I','O','U') and 
    SUBSTRING(city,-1,1) in ('A','E','I','O','U');

Answer 6

您可以对第一个和最后一个字符进行子字符串化并将其与 IN 关键字进行比较，

WHERE SUBSTRING(NAME,1,1) IN (a,e,i,o,u) AND SUBSTRING(NAME,-1) IN (a,e,i,o,u) 

Answer 7

SELECT distinct CITY 
FROM STATION 
where (CITY LIKE 'a%' 
    OR CITY LIKE 'e%' 
    OR CITY LIKE 'i%' 
    OR CITY LIKE 'o%'
    OR CITY LIKE 'u%'
) AND (CITY LIKE '%a' 
    OR CITY LIKE '%e'
    OR CITY LIKE '%i'
    OR CITY LIKE '%o'
    OR CITY LIKE '%u'
)

Answer 8

您可以使用以下正则表达式并反转结果：

^[^aeiou]|[^aeiou]$

即使输入由单个字符组成，这也有效。它应该可以跨不同的正则表达式引擎工作。

MySQL

SELECT city
FROM (
    SELECT 'xx' AS city UNION
    SELECT 'ax'         UNION
    SELECT 'xa'         UNION
    SELECT 'aa'         UNION
    SELECT 'x'          UNION
    SELECT 'a'
) AS station
WHERE NOT city REGEXP '^[^aeiou]|[^aeiou]$'

PostgreSQL

WHERE NOT city ~ '^[^aeiou]|[^aeiou]$'

甲骨文

WHERE NOT REGEXP_LIKE(city, '^[^aeiou]|[^aeiou]$')`

SQL服务器

没有正则表达式支持。使用LIKE带有方括号的子句：

WHERE city LIKE '[aeiou]%' AND city LIKE '%[aeiou]'