AppletTalk.com Java discussions newsgroups   Archives   FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in to check your private messages   Log in  primary key in DAO pattern          AppletTalk.com Forum Index -> Java and Databases View previous topic :: View next topic   Author Message f Guest Posted: Mon Dec 08, 2003 3:18 pm    Post subject: primary key in DAO pattern I am writing a system which is going to be used on different databases. I use the DAO design pattern. The idea is that my system focus on business logic only and it is up to the implementation of the DAO that links my system to different databases with different schema. My question is how to design the primary key in my system for each data piece. I think the key is nessary for me when I write this system, even though I know my system is to used differently, because sometimes I need to join the data or whatever. And the key needs to be translated to different databases when DAO is implemented. DO I need the primary key for my Data? How to design the key so it can be easily implemented by different database? THanks, ff Back to top Petarian Guest Posted: Tue Dec 09, 2003 11:19 am    Post subject: Re: primary key in DAO pattern Hello, I think that if you use an integer as a primary key, that should work in an hetrogeneous enviroment. DO NOT use an auto incrementing integer as some database do not support that. Another suggestion is to have your clients use a third party tool that generates the DAO classes. This way you will know how the keys will be generated. One such tool is DB Architect (http://www.synametrics.com) Regards, Pete f wrote: Quote: I am writing a system which is going to be used on different databases. I use the DAO design pattern. The idea is that my system focus on business logic only and it is up to the implementation of the DAO that links my system to different databases with different schema. My question is how to design the primary key in my system for each data piece. I think the key is nessary for me when I write this system, even though I know my system is to used differently, because sometimes I need to join the data or whatever. And the key needs to be translated to different databases when DAO is implemented. DO I need the primary key for my Data? How to design the key so it can be easily implemented by different database? THanks, ff -- You don't pay to get spam, why pay to clean it? Visit http://www.spammarshall.com to create an account for free <http://www.spammarshall.com> Back to top Display posts from previous: All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First         AppletTalk.com Forum Index -> Java and Databases All times are GMT Page 1 of 1   Jump to: Select a forum Java Newsgroups----------------Java DiscussionsWeb-based java games comp.lang.java 3D Graphics API's for Java Java: Support and criticism Java System Announcements comp.lang.java.api JavaBeans Java and CORBA Java and Databases comp.lang.java.developer Java GUI Toolkits Java Help comp.lang.java.javascript JVM, native methods and hardware comp.lang.java.misc Java Language Programming Security and Java comp.lang.java.setup Java Software Tools comp.lang.java.tech ibm.software.java.linux  Non-English Java Newsgroups----------------Java Language (German)Language Java (Français)Java (Italian)  You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum Powered by phpBB © 2001, 2006 phpBB Group SEO toolkit © 2004-2006 webmedic.