> Now, whenever I insert into this table I want to set date_create to > CURRENT_TIMESTAMP. > > Whenever I update a row I want date_lch (lch=last change) to be set to > CURRENT_TIMESTAMP. (Changes to the date_create col should be (silently) > 'ignored'.
If you feel you cannot trust applications to correctly set the date and time stamp you're effectively creating a 'read only' column. This isn't possible with most sql engines because they don't have column level permissions. You probably want to put the date and time stamp in a separate related table and grant no modify permissions to that table.