https://data.stackexchange.com/stackoverflow/query/4803/so3087921
DECLARE @temp AS TABLE (hex char(6))
INSERT INTO @temp
VALUES ('3333CC') -- Should convert to Red: 51 Green: 51 Blue: 204
DECLARE @table AS varchar(16)
SET @table = '0123456789abcdef' -- Assuming case-insensitive collation!
SELECT hex
,16 * (CHARINDEX(SUBSTRING(hex, 1, 1), @table) - 1) + (CHARINDEX(SUBSTRING(hex, 2, 1), @table) - 1) AS R
,16 * (CHARINDEX(SUBSTRING(hex, 3, 1), @table) - 1) + (CHARINDEX(SUBSTRING(hex, 4, 1), @table) - 1) AS G
,16 * (CHARINDEX(SUBSTRING(hex, 5, 1), @table) - 1) + (CHARINDEX(SUBSTRING(hex, 6, 1), @table) - 1) AS B
FROM @temp
https://dpatrickcaldwell.blogspot.com/2009/05/converting-hexadecimal-or- binary-to.html中有一个通用函数
我通常尽可能地避免使用标量函数，因为有可能诱使自己认为可以为500万行调用标量UDF，而不会对内联表达式造成任何损失。
您还可以使用内联表值UDF：
CREATE FUNCTION dbo.udf_HexToRGB (@hex char(6))
RETURNS TABLE
AS RETURN
(
SELECT 16 * (CHARINDEX(SUBSTRING(@hex, 1, 1), '0123456789abcdef') - 1) + (CHARINDEX(SUBSTRING(@hex, 2, 1),
'0123456789abcdef') - 1) AS R
,16 * (CHARINDEX(SUBSTRING(@hex, 3, 1), '0123456789abcdef') - 1) + (CHARINDEX(SUBSTRING(@hex, 4, 1),
'0123456789abcdef') - 1) AS G
,16 * (CHARINDEX(SUBSTRING(@hex, 5, 1), '0123456789abcdef') - 1) + (CHARINDEX(SUBSTRING(@hex, 6, 1),
'0123456789abcdef') - 1) AS B
)
GO
DECLARE @temp AS TABLE (hex char(6))
INSERT INTO @temp
VALUES ('3333CC') -- Should convert to Red: 51 Green: 51 Blue: 204
SELECT hex
,R
,G
,B
FROM @temp
OUTER APPLY dbo.udf_HexToRGB(hex)
602392714
清零编程群