Re: Nulls in Informix

In response to my post on using default values instead of nulls, Nils Myklebust wrote: > Yes, but you would have the significant problem that you would have to > analyze every insert into the table and leave out any column that had > a null value in your application. If it is included in the insert you > get an error, not the default value. I think Date, Darwen and others > are of the opinion that simpler solutions for this problem should be > implemented in the engine. At worst, this is a simple if-test when you generate your DML. Good high-level application interfaces, like Microsoft's ADO, can take care of such trivia automagically. It's no show stopper. > I think Date, Darwen and others > are of the opinion that simpler solutions for this problem should be > implemented in the engine. I don't understand what this means. The use of null introduces another truth value, which affects the entire relational model. At any rate, Date and Darwen were the first to advocate using default values instead of nulls to solve the missing information problem. See Date's _Introduction to Database Systems_,_Sixth_Edition_, Chapter 20, for commentary and references. Date has hinted that he thinks an even better solution is possible, but I've seen nothing concrete. -J-