If you don't want to allow multiple entries then you can make one (or more) of the fields a primary key. Then just trap the SQL error if you try to enter it twice. This way the SQL server is the one doing the checking which is better for overall consistancy.
Matt Quoting Peter Huber <[EMAIL PROTECTED]>: > Hi, > > create an updateable Statement, this is the create statement method > with the two parameters. > Then you can: > 1. Try a "Select * from <your_table> where <xyz> = <your_form_id>" > 2. Try if(rs.next()) > 2.1 TRUE: entity exists already, with updateable select you can > immediately change the entities values within the current resultset > row > (use the set Methods) > 2.2 FALSE: entity does NOT exist: Use the ResultSet 'navigation' > methods to navigate it to the 'insert row' (ResultSet.moveToInsertRow > ()). set your values with the set methods. Finally call > ResultSet.insertRow(). > > ATTENTION: I think this is a very special feature, so it may work in > theory but not with your jdbc-driver. Better create a prototype first > to figure out your drivers capabilities. > > Another way would be to have a primary key constraint on your table > for > the very id (or unique key if you have another primary). > Then you may use a try-and-see approach which always uses "INSERT" > statements. If you try to insert entity with id which is already in db > you going to get a exception. Act upon that exception by propagating > it > or use a "UPDATE" now. > > Peter > > > ----- Original Message ----- > From: mike dizon <[EMAIL PROTECTED]> > Date: Wednesday, November 21, 2001 4:42 am > Subject: verifying database entries > > > Hi All, > > > > I'm trying to make sure that an entry in a database doesn't exist > > before I enter data into the database -- based on information > > entered in on a form. > > > > How do I go about doing that? Any help would be appreciated. > > > > Thanks > > MD > > > > > > > > ___________________________________________________________________________ > To unsubscribe, send email to [EMAIL PROTECTED] and include in the > body > of the message "signoff SERVLET-INTEREST". > > Archives: http://archives.java.sun.com/archives/servlet-interest.html > Resources: > http://java.sun.com/products/servlet/external-resources.html > LISTSERV Help: http://www.lsoft.com/manuals/user/user.html > ___________________________________________________________________________ To unsubscribe, send email to [EMAIL PROTECTED] and include in the body of the message "signoff SERVLET-INTEREST". Archives: http://archives.java.sun.com/archives/servlet-interest.html Resources: http://java.sun.com/products/servlet/external-resources.html LISTSERV Help: http://www.lsoft.com/manuals/user/user.html
