Bu makalemizde bir string i base64 e encode eden function u paylaşıyoruz.
- Yazılım Uzmanları
- 16 Mart 2022
- 932 kez görüntülendi.
Bu makalemizde bir string i base64 e encode eden function u paylaşıyoruz.
ALTER function [dbo].[fnBase64Encode] ( @plain_text varchar(6000)) RETURNS varchar(8000) AS BEGIN --local variables DECLARE @output varchar(8000), @input_length integer, @block_start integer, @partial_block_start integer, -- position of last 0, 1 or 2 characters @partial_block_length integer, @block_val integer, @map char(64) SET @map = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/' --initialise variables SET @output = '' --set length and count SET @input_length = LEN( @plain_text + '#' ) - 1 SET @partial_block_length = @input_length % 3 SET @partial_block_start = @input_length - @partial_block_length SET @block_start = 1 --for each block WHILE @block_start < @partial_block_start BEGIN SET @block_val = CAST(SUBSTRING(@plain_text, @block_start, 3) AS BINARY(3)) --encode the 3 character block and add to the output SET @output = @output + SUBSTRING(@map, @block_val / 262144 + 1, 1) + SUBSTRING(@map, (@block_val / 4096 & 63) + 1, 1) + SUBSTRING(@map, (@block_val / 64 & 63 ) + 1, 1) + SUBSTRING(@map, (@block_val & 63) + 1, 1) --increment the counter SET @block_start = @block_start + 3 END IF @partial_block_length > 0 BEGIN SET @block_val = CAST(SUBSTRING(@plain_text, @block_start, @partial_block_length) + REPLICATE(CHAR(0), 3 - @partial_block_length) AS BINARY(3)) SET @output = @output + SUBSTRING(@map, @block_val / 262144 + 1, 1) + SUBSTRING(@map, (@block_val / 4096 & 63) + 1, 1) + CASE WHEN @partial_block_length < 2 THEN REPLACE(SUBSTRING(@map, (@block_val / 64 & 63 ) + 1, 1), 'A', '=') ELSE SUBSTRING(@map, (@block_val / 64 & 63 ) + 1, 1) END + CASE WHEN @partial_block_length < 3 THEN REPLACE(SUBSTRING(@map, (@block_val & 63) + 1, 1), 'A', '=') ELSE SUBSTRING(@map, (@block_val & 63) + 1, 1) END END --return the result RETURN @output END
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