Jay Kang wrote:
Hello, I'm currently trying to decide on a database design for tags in my web 2.0application. The problem I'm facing is that I have 3 separate tables i.e. cars, planes, and schools. All three tables need to interact with the tags, so there will only be one universal set of tags for the three tables. I read a lot about tags and the best articles I found were: Road to Web 2.0 ( http://wyome.com/docs/Road_to_Web_2.0:_The_Database_Design )
And what in particular recommended this to you?
Currently, this is my DB design: Cars (carid, carname, text, etc.) Planes (planeid, planename, text, etc.) Schools (schoolname, text, etc.) <------ School does not take int as primary key but a varchar.
You don't mention a primary-key here at all. You're not thinking of using "schoolname" are you?
Tags (tagid, tagname, etc) --- Now here is where I have the question. I have to link up three separate tables to use Tags --- So when a new car is created in the Cars table, should I insert that carID into the TagsItems table --- as itemID? So something like this? TagsItems ( tagid INT NOT NULL REFERENCES Tags.TagID, itemid INT NULL, <---- really references Cars.carID and Planes.planeID schoolname varchar NULL <---- Saves the Schools.schoolname itemid + tagId as Unique )
What's wrong with the completely standard: car_tags (carid, tagid) plane_tags (planeid, tagid) school_tags (schoolid, tagid)
I also have a question on the schoolname field, because it accepts varchar not integer. There seems to be some design that would better fit my needs. I'm asking you guys for a little assistance.
Sorry, don't understand this question. -- Richard Huxton Archonet Ltd ---------------------------(end of broadcast)--------------------------- TIP 6: explain analyze is your friend
