大写字母或小写字母转换为数字

大写字母或小写字母转换为数字A-->1,a-->1;B-->2,b-->2;C-->3,c-->3;...Z-->26,z-->26
 如果非字母转换为-1

 

SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO

-- =============================================
-- Author:      Insus.NET
-- Blog:        https://insus.cnblogs.com
-- Create date: 2019-05-23
-- Update date: 2019-05-23
-- Description: 大写字母或小写字母转换为数字A-->1,a-->1;B-->2,b-->2;C-->3,c-->3;...Z-->26,z-->26
--                如果非字母转换为-1
-- =============================================
CREATE FUNCTION [dbo].[svf_ConvertLetterToNumber] 
(
  @letter CHAR(1)
) RETURNS INT
AS
BEGIN
    DECLARE @ascii INT = -1
    IF LEN(ISNULL(@letter,\'\')) > 0 
    BEGIN        
        IF ASCII(@letter) % 65 + 1 <= 26
            SET @ascii = ASCII(@letter) % 65+ 1

        IF ASCII(@letter) % 97 + 1 <=26
            SET @ascii = ASCII(@letter) % 97 + 1
    END        
    
    RETURN @ascii
END
GO

Source Code

 

演示：

 

SELECT 
[dbo].[svf_ConvertLetterToNumber](\'A\') AS [A],
[dbo].[svf_ConvertLetterToNumber](\'a\') AS [a],
[dbo].[svf_ConvertLetterToNumber](\'B\') AS [B],
[dbo].[svf_ConvertLetterToNumber](\'b\') AS [b],
[dbo].[svf_ConvertLetterToNumber](\'C\') AS [C],
[dbo].[svf_ConvertLetterToNumber](\'c\') AS [c],
[dbo].[svf_ConvertLetterToNumber](\'Z\') AS [Z],
[dbo].[svf_ConvertLetterToNumber](\'z\') AS [z],
[dbo].[svf_ConvertLetterToNumber](\'@\') AS [@],
[dbo].[svf_ConvertLetterToNumber](\'$\') AS [$]
GO

Source Code