I have database A with an nvarchar(max) column containing images. The data was copied to database B with Sql Data Compare. Both columns are SQL_Latin1_General_CP1_CI_AS collation. When I save the data to a file from each database and compared using beyond compare, the image in database b had an invalid jpeg marker but otherwise beyond compare was able to display the image.
Looking at the data in SSMS, the first character of the good image starts with a box while the bad image first character starts with a diamond.
When I compare the two tables with SQL Data Compare, at first no differences were seen. When I set the comparison to use binary collation, then differences were seen, but when I updated database b, the first character remained a diamond instead of a box. When Sql Data Compare displays the side by side data, both columns show a diamond as the first character rather than showing a box for the column from database A.
For some reason Sql Data Compare is not correctly reading the data from the database during its comparison.
I used SSMS to update the data in database b and the images are all fine.