sqlserver 截取字符串中的汉字

CREATE function getNames(@s varchar(500))
returns varchar(200)
as 
begin
DECLARE
  @temp VARCHAR ( MAX ) = ''
  if len(@s) = 0 or @s is null
  return '无'  
SELECT
  @temp = @temp + SUBSTRING ( ch, sv.number, 1 ) 
FROM
  ( SELECT @s AS ch ) t CROSS APPLY [master].dbo.spt_values AS sv 
WHERE
  sv.type = 'P' 
  AND sv.number BETWEEN 1 
  AND LEN( ch ) 
  AND (UNICODE( SUBSTRING ( ch, sv.number, 1 ) ) BETWEEN 19968
  AND 40869 or UNICODE ( SUBSTRING ( ch, sv.number, 1 ) ) = 125)  
  set @temp = replace( @temp ,'}',',')
  set @temp = substring(@temp,1,len(@temp)-1)
return @temp
end