Question

I have a c# function that needs to write to a SQL image column. I have the image in a byte array. The standard seems to be the use of SqlCommand while passing the byte array as a parameter of type System.Data.SqlDbType.Image.

Unfotunately, my function can only use text queries (don’t ask why) so I have to find a way to use T-SQL commands only. What I have so far can write to the column but I don’t know what format of string to make the image blob string.

sql = "DECLARE @ptrval binary(16)" +
"SELECT @ptrval = textptr(Photo) FROM EMPhoto WHERE Employee='" + employeeID + "'" +
"WRITETEXT EMPhoto.Photo @ptrval " + imageByteArrayAsString;

I’ve tried converting imageByteArray to a Hex string and Binary string but it doesn’t seem to end up correct in SQL or in the application that reads it.

Answer 1

A T-SQL Binary constant is an unquoted hexidecimal string prefixed with 0x. ie 0xFFD8FFE0…

string imageByteArrayAsString = "0x" + BitConverter.ToString(image).Replace("-", string.Empty);