How to save a byte array (byte[]) in a database and retrive it back as byte array?

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  12 years ago

  by theforgotten

  Ashutosh Agarwal

  London, United Kingdom

  Joined 12 years ago
  Hello, I am working on a project which aims to compare an image to from a database of images and find out similar looking images. I am working with a DLL file which returns unique hash for each image. The hash is an array of 768 bytes. (byte[]) My problem is how can I store this byte[] in database and later retrive it back as a byte[]? I have tried many methods like storing it in a varbinary and varchar format but when I look in the database, its just a long number (might be string) and there is no information about which element goes where in array if that makes sense?? SqlCommand cmd1 = new SqlCommand("INSERT INTO SIMILAR (ImageHash, ID) VALUES ((@hash), 26)", con); byte[] hash1 = GetHash(path1, 1); byte[] hash2 = GetHash(path2, 1); cmd1.Parameters.AddWithValue("@hash", hash1); The reason why I need the data back as byte[] is that one of the DLL function takes two byte arrays and compare them for similarity. Any help is greatly appreciated. Ash
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  12 years ago

  by a0davida

  David Alcalay

  Jerusalem, Israel

  Joined 12 years ago
  Hi, The data type of the field has to image (or another type of blob) and then you can send it to the command as a parameter like you did. For retriving you have to cast the resault to a byte array. For example: DataTable dt = dal.GetData(); byte[] b = (byte[])dt.rows[0]["imageField"]; David
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  12 years ago

  by theforgotten

  Ashutosh Agarwal

  London, United Kingdom

  Joined 12 years ago
  Hi David, Thank you very much. That solved the problem. I was able to save it but was having problems retrieving it. But now its solved. Thank you once again. :)
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