[thelist] MySQL data types

[noah]

Sorry if this is a stupid question.

I've been using tinyint in MySQL tables in order to build relationships 
between tables (i.e., to normalize).

The problem I've just encountered is that even if the default for a tinyint 
column is set to be null, if a record is entered without information for 
that column, the value is set to 0 (i.e., it isn't null), which causes 
problems when extracting data from the database.

I'm surprised I haven't run into this before, but this is the first time 
it's gotten in my way. Is there any way of dealing with this other than 
changing the data type to char, or something like that? I've searched the 
MySQL manual, but I can't find anything relating to this (probably just 
because I can't get the right search phrase).

And so that I don't have to bug people with questions like this in the 
future, can anyone recommend a good, thorough MySQL book?

Thanks,
Noah