SQL Server Insert Varbinary - sql

Question

I need to take a Varbinary(max) from a SQL Server column and insert it into another varbinary column, however my image does not render when displayed via the new field, what am I doing wrong?
I've copied from SQL Server, ie
E7D28201A240202178EF491E413EB4DDBCFB54A15077A989A37A0C5E4E0F143AEE7000CE3F3A70C0E4F342E524C8F4A7243888AA581EC051B030E7A8EF4E233DF.....
and then
update client
set Photo = convert(varbinary(max),'E7D28201A240202178EF491E413EB4DDBCFB54A15077A989A37A0C5E4E0F143AEE7000CE3F3A70C0E4F342E524C8F4A7243888AA581EC051B030E7A8EF4E233DF.....')
where id='40946b09-81be-42b0-ae62-63182acb1e89'

Answer 1

The data is not Base64 encoded as that would have a much larger range of alpha characters, whereas this value is pure hex values (i.e. 0-9, A-F). Also, the example HTML code provided by the O.P. (in a comment on the Question) is:
<img src="data:image;base64,#System.Convert.ToBase64String(Model.PhotoDisplay)
which shows that the source value of Model.PhotoDisplay is first converted to Base64 so that the data:image;base64 type designation will be correct.
The problem is that SQL Server, when asked to convert the value, does not know that it is already a hex/binary string. You need to tell SQL Server what the format of the source data is. This can be done in two ways:
Depending on how you are building this value, you just need to add the 0x prefix and remove the single-quotes:
UPDATE cl
SET cl.Photo = CONVERT(VARBINARY(MAX), 0xE7D28201A24020.....)
FROM Client cl
WHERE cl.[id] = '40946b09-81be-42b0-ae62-63182acb1e89';
If you need to keep the value as a string, and are using SQL Server 2008 or newer, then you can use the "style" option of the CONVERT function to tell SQL Server that it is a binary value, and you have the additional option of
adding the 0x prefix and using a "style" of 1:
UPDATE cl
SET cl.Photo = CONVERT(VARBINARY(MAX), '0xE7D28201A24020.....', 1)
FROM Client cl
WHERE cl.[id] = '40946b09-81be-42b0-ae62-63182acb1e89';
keep the value without the 0x prefix and using a "style" of 2:
UPDATE cl
SET cl.Photo = CONVERT(VARBINARY(MAX), 'E7D28201A24020.....', 2)
FROM Client cl
WHERE cl.[id] = '40946b09-81be-42b0-ae62-63182acb1e89';
But, if this data really is coming from a VARBINARY(MAX) field in another table, then how is it ending up as a string in the first place? The easiest way to move this is to either:
Transfer the data directly between tables:
UPDATE cl
SET cl.Photo = src.SomeField
FROM Client cl
INNER JOIN SomeTable src
ON src.JoinField = cl.JoinField
WHERE something? = somethingElse?;
Use a VARBINARY(MAX) variable:
DECLARE #Photo VARBINARY(MAX);
SELECT #Photo = src.photo
FROM SomeTable src
WHERE src.SomeField = ?;
UPDATE cl
SET cl.Photo = #Photo
FROM Client cl
WHERE cl.[id] = '40946b09-81be-42b0-ae62-63182acb1e89';

Answer 2

Why not copy it directly using an SQL statement, rather than copy/pasting from SSMS?
I'll leave an example to copy the data from another client (bogus id for the example):
UPDATE client
SET Photo = (SELECT Photo FROM client WHERE id='00000000-0000-0000-0000-000000000000')
WHERE id='40946b09-81be-42b0-ae62-63182acb1e89';