Re: A problem in SQL (a real challenge)
Date: 2000/05/11
Message-ID: <391A66CE.F4CC323B_at_medicina.ub.es>#1/1
Thomas Muller wrote:
> In general I agree, hence the statement "Do note that a table without a
> primary key violates 1NF, hence should
> generally be avoided." in my last reply. --
It's obvious that a table have to have a primary key, but I don't agree that a table without a primary key violates 1NF. The definition of 1NF is that the table has no repeating groups and that all columns are scalar, the value of a column in a row is atomic, is not an array for example. As Joe Celko say in his book, SQL not support arrays and structured data but you may "fake it" in SQL putting a group of columns in wich all the members of the group represent the same attribute in the table. But I thing this is independent of the concept of primary key.