Hi, I just start using pgsql and I am new to SQL also. I have read lots of documents on this and I cant seem to find the answer, perhaps you can help me. Say I have a table: pgsql=> \d test_table test_table ------------------------------ f1| CHAR (40) f2| CHAR (40) Somewhere down the line I need to change the data type on f2 to CHAR (50) and add constrains like UNIQUE. What is the best was to change tables in this way? Can I just make a new table the way I want and COPY the data out of the old table and COPY it back in? do I use CAST ? Is there some ALTER TABLE tablename MODIFY command I can use? This question has been bugging me for awhile. Because I am new to SQL I find that I make bad design choices about data types and such all the time. So I need to know the best way to change them. Richard
