在 MySQL 中将十六进制转换为二进制
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Convert hex to binary in MySQL
提问by Dels
Currently I search a function in MySQL to do conversion between hex string to binary representation, example:
目前我在 MySQL 中搜索一个函数来在十六进制字符串到二进制表示之间进行转换，例如：
0000 -> 0000000000000000
00AA -> 0000000010101010
FFFF -> 1111111111111111
I have already tried
我已经试过了
UNHEX('00AA')
CAST('00AA' AS BINARY)
CONVERT('00AA', BINARY)
but didn't get the results I want.
但没有得到我想要的结果。
回答by ypercube??
Use CONV()function:
使用CONV()功能：
CONV(string, 16, 2)
To have length according to input:
根据输入有长度：
LPAD(CONV(string, 16, 2), LENGTH(string)*4, '0')
As CONV()works with 64-bit precision, you can't have more than 64 bits converted, so you can use this as well:
由于CONV()使用 64 位精度，您不能转换超过 64 位，因此您也可以使用它：
LPAD(CONV(string, 16, 2), 64, '0')
and you should check that LENGTH(string) <= 16or you may get erroneous results.
你应该检查一下，LENGTH(string) <= 16否则你可能会得到错误的结果。
回答by u557022
UNHEX('hex string')
Would interpret each pair of characters in a string passed into the function as two hex characters and try to convert that to a binary number (binary format in mysql). This way, you can convert a string to binary. However, this won't display the content as a string of binary digits. Rather, each 2 bytes in the resulting string converted to the specific character encoding (for example utf8).
将传递给函数的字符串中的每一对字符解释为两个十六进制字符，并尝试将其转换为二进制数（mysql 中的二进制格式）。这样，您可以将字符串转换为二进制。但是，这不会将内容显示为一串二进制数字。而是将结果字符串中的每 2 个字节转换为特定的字符编码（例如 utf8）。
