sql 随笔 2015-07-02

sql 自定义函数

 --检查函数是否存在

 if exists (select * from dbo.sysobjects where id = object_id(N'dbo.pTitleCase') and xtype in (N'FN', N'IF', N'TF'))    

  drop function dbo.pTitleCase  ;

 go



--创建函数

create function dbo.pTitleCase(@strIn nvarchar(Max))

	returns nvarchar(Max)

as 

	begin;

		declare

		@strOut nvarchar(max),

		@currentPostion int,

		@nextSpace int,

		@currentWord nvarchar(max),

		@strLen int,

		@lastWord bit;

	

	set @nextSpace = 1;

	set @currentPostion =1;

	set @strOut ='';

	set @strLen=Len(@strIn);

	set @lastWord=0;

	

	while @lastWord=0

		begin;

			set @nextSpace=CharIndex( ' ',@strIn,@currentPostion+1)

			if @nextSpace=0 --no more spaces found

				begin;

					set @nextSpace=@strLen;					

					set @lastWord=1;

				end;

			

			set @currentWord = Upper(substring(@strIn,@currentPostion,1));

			set @currentWord = @currentWord + lower(substring(@strin,@currentPostion+1,@nextSpace-@currentPostion));

			set @strOut=@strOut+@currentWord;

			set @currentPostion=@nextSpace+1;

		end;

	return @strOut;

end;

go	



--执行函数

SELECT [Demo].[dbo].[pTitleCase] ( 'one TWO tHrEe')

go