SqlServer 获取汉字的拼音首字母

一、该函数传入字符串，返回数据为：如果为汉字字符，返回该字符的首字母，如果为非汉字字符，则返回本身。
二、用到的知识点：汉字对应的UNICODE值，汉字的排序规则。
三、数据库函数：

CREATE FUNCTION GetInitialLetter(@ChineseString NVARCHAR(4000))
RETURNS NVARCHAR(4000)
AS
BEGIN

DECLARE @SingleCharacter NCHAR(1),
@ReturnString NVARCHAR(4000)
SET @ReturnString = '' 

WHILE LEN(@ChineseString)>0
BEGIN

--依次取单个字符
SET @SingleCharacter = LEFT(@ChineseString,1) 

----汉字字符，返回字符对应首字母,非汉字字符,返回原字符
IF(UNICODE(@SingleCharacter) BETWEEN 19968 AND 19968+20901)
SET @ReturnString = @ReturnString +
(SELECT TOP 1 PY FROM
(SELECT 'A' AS PY,N'骜' AS ChineseCharacters
UNION All SELECT 'B',N'簿'
UNION All SELECT 'C',N'错'
UNION All SELECT 'D',N'鵽'
UNION All SELECT 'E',N'樲'
UNION All SELECT 'F',N'鳆'
UNION All SELECT 'G',N'腂'
UNION All SELECT 'H',N'夻'
UNION All SELECT 'J',N'攈'
UNION All SELECT 'K',N'穒'
UNION All SELECT 'L',N'鱳'
UNION All SELECT 'M',N'旀'
UNION All SELECT 'N',N'桛'
UNION All SELECT 'O',N'沤'
UNION All SELECT 'P',N'曝'
UNION All SELECT 'Q',N'囕'
UNION All SELECT 'R',N'鶸'
UNION All SELECT 'S',N'蜶'
UNION All SELECT 'T',N'箨'
UNION All SELECT 'W',N'鹜'
UNION All SELECT 'X',N'鑂'
UNION All SELECT 'Y',N'韵'
UNION All SELECT 'Z',N'咗'
)SpellingTable
where ChineseCharacters > = @SingleCharacter COLLATE Chinese_PRC_CS_AS_KS_WS
ORDER by PY ASC)
ELSE
SET @ReturnString = @ReturnString + @SingleCharacter

SET @ChineseString = RIGHT(@ChineseString,LEN(@ChineseString)-1) 

END

RETURN @ReturnString 

END
GO

SELECT dbo.GetInitialLetter('加油2018')

返回：JY2018