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) ASBEGIN 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)ELSESET @ReturnString = @ReturnString + @SingleCharacter SET @ChineseString = RIGHT(@ChineseString,LEN(@ChineseString)-1) END RETURN @ReturnString ENDGO

SELECT dbo.GetInitialLetter('加油2018')

返回：JY2018