SELECT语句中TRIM特定的列名称

Question

我有一个具有5列“ id”，“ firstname”，“ lastname”，“ age”，“ email”的“ User”表。

是否可以执行此sql命令？

SELECT LTRIM(RTRIM(firstname,lastname,email)) FROM User

我需要选择的是修剪后的3列。

Answer 1

您需要分别修剪每个字段

select ltrim(rtrim(firstname)), ltrim(rtrim(lastname)), ltrim(rtrim(email))
from User

Answer 2

您必须分别处理每列，如下所示：

SELECT LTRIM(RTRIM(firstname)) as firstname,
       LTRIM(RTRIM(lastname)) as lastname,
       LTRIM(RTRIM(email)) as email
FROM [User]

Answer 3

用这个：

SELECT
        LTRIM(RTRIM(FirstName)) AS FirstName,
        LTRIM(RTRIM(LastName)) AS LastName,
        LTRIM(RTRIM(Email)) AS Email
FROM    User

您需要分别对所有列进行TRIM。