VPCART gives you more flexibility by adding menu Database
Tool in the administration to allow you to execute any SQL query you may
have written in txt file.
You can access it in the administration menu :
Misc>Database Tool
Example, say you want to add a
new column to Categories table called specialcat with text
field type and field length 5 in the SQL SERVER DB, you may be write as :
ALTER TABLE categories ADD COLUMN specialcat text(5);
And then you can save the SQL syntax into a txt file e.g.
addcustomfields.txt.
You will then upload the txt file into the admin
folder using FTP.
Then you can try to execute it from the Database
Tool menu in the administration, and entering the txt filename that you have
uploaded and click Convert.