Save byte[] into a SQL Server database from C#

How can I save a byte[] array into a SQL Server database? This byte[] contains a HashAlgorithm value.

The data is needed again for later use. So converting it and NOT getting it back in its original state, is not what I want.

Thanks in advance!

You should be able to write something like this:

string queryStmt = "INSERT INTO dbo.YourTable(Content) VALUES(@Content)";

using(SqlConnection _con = new SqlConnection(--your-connection-string-here--))
using(SqlCommand _cmd = new SqlCommand(queryStmt, _con))
{
   SqlParameter param = _cmd.Parameters.Add("@Content", SqlDbType.VarBinary);
   param.Value = YourByteArrayVariableHere;

   _con.Open();
   _cmd.ExecuteNonQuery();
   _con.Close();
}

Using Linq-to-SQL, you'd write something like this:

using(YourDataContextHere ctx = new YourDataContextHere())
{
   SomeClassOfYours item = new SomeClassOfYours();

   item.ByteContent = (your byte content here);

   ctx.SomeClassOfYourses.InsertOnSubmit(item);
   ctx.SubmitChanges();
}

That will insert your byte[] into a column Content of type VARBINARY in your SQL Server table as a byte stream, which you can read back 1:1 again later on.

Use VARBINARY

Varbinary or CHAR - with the value converted to a hex. I do that pretty often with hash values because it allows me to SEE and COMPARE them easily (on rintouts, during development), and the overhead is minimal.

Using Dapper you may save HTML Code easily like this:

using (var con = DapperConnection.Con)
{
    string firstValue = "any text...";
    string secondValue = "HTML code maybe ?";

    // Convert your string into byte array:
    byte[] htmlCode = Encoding.ASCII.GetBytes(secondValue);

    // Define your insert query and execute it:
    con.Execute($@" INSERT INTO [dbo].[YourTableName]
                    ( [firstColumnName], [secondColumnName] )
                    VALUES
                    ( {firstValue}, COMPRESS(@HTML) )", new { HTML = htmlCode });
}

You may then DECOMPRESS it from database like this:

SELECT [firstColumnName], CONVERT(varchar(MAX), DECOMPRESS([secondColumnName])) FROM [YourTableName];