--full2half
CREATE FUNCTION [dbo].[full2half](
@String nvarchar(max)
)
RETURNS nvarchar(max)
AS
/*
全角(Fullwidth)转换为半角(Halfwidth)
*/
BEGIN
    DECLARE @chr nchar(1)
    DECLARE @i int
    SET @String = REPLACE(@String,N'　',N' ')
    SET @i = PATINDEX(N'%[！-～]%' COLLATE Latin1_General_BIN,@String)
    WHILE @i > 0
    BEGIN
        SET @chr = SUBSTRING(@String,@i,1)
        SET @String = REPLACE(@String,@chr,NCHAR(UNICODE(@chr)-65248))
        SET @i = PATINDEX(N'%[！-～]%' COLLATE Latin1_General_BIN,@String)
    END
    RETURN @String
END
GO
CREATE FUNCTION [dbo].[half2full](
@String nvarchar(max)
)
RETURNS nvarchar(max)
AS
/*
半角(Halfwidth)转换为全角(Fullwidth)
*/
BEGIN
    DECLARE @chr nchar(1)
    DECLARE @i int
    SET @String = REPLACE(@String,N' ',N'　')
    SET @i = PATINDEX(N'%[!-~]%' COLLATE Latin1_General_BIN,@String)
    WHILE @i > 0
    BEGIN
        SET @chr = SUBSTRING(@String,@i,1)
        SET @String = REPLACE(@String,@chr,NCHAR(UNICODE(@chr)+65248))
        SET @i = PATINDEX(N'%[!-~]%' COLLATE Latin1_General_BIN,@String)
    END
    RETURN @String
END
GO