Question

使用LTRIM和RTRIM函数删除空格并不像我期望的那样工作：

示例：

SELECT RTRIM(LTRIM('TEST NAME  ')) 
RESULT = 'TEST NAME  ' DOES NOT WORK

SELECT RTRIM(LTRIM('TEST NAME '))
RESULT = 'TEST NAME' IT WORKS

Answer 1

可能你有一些不是空格（制表符）的字符，或者你的字符串以carriage-return / null终止结尾。

Answer 2

实际上，对于我使用SQL Server 2008 R2，它适用于您的两个示例。

证明：

SELECT '"' + RTRIM(LTRIM('TEST NAME  ')) + '"'  
SELECT '"' + RTRIM(LTRIM('TEST NAME ')) + '"'

将给予＆＃34; TEST NAME＆＃34;作为两者的输出。

您的真实数据可能包含除空格之外的其他内容，但您的示例并未说明这一点。

Answer 3

使用此示例代码查找字符串中的任何隐藏字符

-- The @position variable holds the position of the character currently  
-- being processed. The @nstring variable is the Unicode character   
-- string to process.  
DECLARE @position int, @nstring nvarchar(500);  
-- Initialize the current position variable to the first character in   
-- the string.  
SET @position = 1;  
-- Initialize the character string variable to the string to process.   
-- Notice that there is an N before the start of the string, which   
-- indicates that the data following the N is Unicode data.  
SET @nstring = N'TEST NAME  ';  
-- Print the character number of the position of the string you are at,   
-- the actual Unicode character you are processing, and the UNICODE   
-- value for this particular character.  
PRINT 'Character #' + ' ' + 'Unicode Character' + ' ' + 'UNICODE Value';  
WHILE @position <= DATALENGTH(@nstring)  
-- While these are still characters in the character string,  
   BEGIN;  
   SELECT @position,   
      CONVERT(varchar, SUBSTRING(@nstring, @position, 1)),  
      UNICODE(SUBSTRING(@nstring, @position, 1));  
   SELECT @position = @position + 1;  
   END;

来源https://docs.microsoft.com/en-us/sql/t-sql/functions/unicode-transact-sql

Answer 4

您可以使用替换：

删除控制字符CHAR（10）和CHAR（13）

SELECT RTRIM(LTRIM(REPLACE(REPLACE('TEST NAME  ', CHAR(13), '')
                          ,CHAR(10), '')
                  )
            )

为什么我使用LTRIM和RTRIM获取空格值？

4 个答案: