we have a database in our Java program which holds information about registered users, etc. and I am a complete database noob.
Now in sql there is this ALTER TABLE ... ADD COLUMN syntax, which lets you add a column to an existing table.

Now I want to know how I can skip this if the table already has the column?
So the syntax for "if table x has column y, don't add it". It needs to be conform with the executeUpdate(String sql) method from the interface Statement.

Any idea?