Convert SQL Binary to byte array

Question

Given some data stored in a SQL binary field:

0x83C8BB02E96F2383870CC1619B6EC...

I'd like to convert it into a byte array, but it doesn't seem like I can just cast this directly into a byte like so:

byte[] someBytes = (byte) 0x83C8BB02E96F2383870CC1619B6EC...;

What am I missing here?

Uh? Querying the DB for a binary field will return a byte array. — Diego Mijelshon, Oct 12 '10 at 15:07
Say I'm in Query Analyzer, and I SELECT from a binary field, the result grid has the value from above (I truncated the example because it's over 300 characters long). — JMP, Oct 12 '10 at 15:10

score 5 · Accepted Answer · answered Oct 12 '10 at 15:12

5

The data stored in the SQL field is in binary. The '0x83..' string you quoted is just a hexadecimal representation of that binary data.

If you just want to copy/paste the hexadecimal data into your C# code (as you seem to have written), then you'll need to convert it from hexadecimal to binary. .NET provides a (rather obscure) class for this sort of thing:

using System.Runtime.Remoting.Metadata.W3cXsd2001.SoapHexBinary

public byte[] ToBytes(string hex)
{
    var shb = SoapHexBinary.Parse(hex);
    return shb.Value;
}

public void TestConvert()
{
    byte[] someBytes = ToBytes("83C8BB02E96F2383870CC1619B6EC");
}

If your binary data is coming from your database in a different form than a copy/pasted string, you'll need to provide more information about your setup.

answered Oct 12 '10 at 15:12

ladenedge

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Removing the `0x` from the string is a subtle but important difference between the data that would be copied and the example here. Without doing that you will get `xsd:hexBinary` errors – StingyJack Jun 16 '20 at 19:37
I'm getting `xsd:hexBinary invalid` errors even after removing the `0x`. Edit: removing one character from the end (to make the length even, I suppose) fixed it. – georgiaboy82 Jul 06 '20 at 18:14
Is there a way to do this in .NET Core? I can't find an analogous library – codeMonkey Aug 12 '22 at 23:12

score 4 · Answer 2 · answered Jul 02 '18 at 13:28

4

Your casting is wrong.

byte[] someBytes = (byte[]) 0x83C8BB02E96F2383870CC1619B6EC...;

I had the same problem and I stumbled across this question. After further research I tried casting like the above and it worked.

answered Jul 02 '18 at 13:28

full-stack

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I'm getting error "Integral constant is too large". Any ideas? – codeMonkey Aug 12 '22 at 23:13

score 0 · Answer 3 · answered Aug 15 '22 at 15:24

Stolen from this answer:

Remove the 0x from the beginning of your data and create a string:

var stringHex = "83C8BB02E96F2383870CC1619B6EC...";

Then convert to byte[] with this method:

byte[] myArray = Enumerable.Range(0, stringHex.Length / 2)
                           .Select(x => Convert.ToByte(stringHex.Substring(x * 2, 2), 16))
                           .ToArray();

I had to use this method because my data was too long, so I was getting errors about Int32 and Int64 overflow.

Convert SQL Binary to byte array

3 Answers3

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