sql-server - LTRIM 和 RTRIM 精确修剪哪些字符？

Question

LTRIM 和 RTRIM are documented to trim "blanks" .哪些字符被视为“空白”？

Answer 1

好问题。虽然有很多whitespace Unicode定义的字符，只去掉一个空格(0x0020):

with Characters as (
  select NChar( 0 ) as Character
  union all
  select NChar( Unicode( Character ) + 1 )
    from Characters
    where Unicode( Character ) < 65535 ),
  CharacterMap as (
  select Unicode( Character ) as [UnicodePoint], Character,
    1 - Len( LTrim( Character ) ) as [Whitespace]
    from Characters )
  select UnicodePoint, Character, Whitespace
    from CharacterMap
    where Whitespace = 1
    option ( MaxRecursion 0 );

(同样适用于RTrim。)