Well, there's certainly no way that is adopted by everybody. I would recommend having a primary key for each table. In your case maybe a line number that with the foreign key would constitute a primary key would work. Some people feel that every table should have an artificial key. One that's generated by the system and has no other meaning. Others think natural keys are fine. I don't think it matters that much. The most important thing is ensuring that you'll never have duplication. You may want to go as far as creating a primary index on all the fields. That way you'll never run into a situation where someone intentionally adds duplicate records then accidently deletes or updates all of them. The main disadvantage of having a lot of fields in your primary key is performance. That will really depend on how many fields there are and how big the table is.

>Last question... Which is the common way adopted by everybody...
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>I'm sure that if i select all the fields in view, it will be unique..
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>Pls advs...