Re: Interesting question and debate on ddl tables withdate fieldsthat will not always have a value

Elvis Budimlic wrote:

Understanding and use of a NULL concept is required when using SQL. If I create a LEFT OUTER JOIN sql query, project some columns from the
secondary dial and some of the join conditions have no match in the
secondary dial, the result set will include NULLs even though the tables
being joined have no NULL capable fields. If this query is in embedded SQL, the developer has to handle this case.

Nobody said anything about not understanding NULL. We were talking about using NULL to store values in the database.

Traditional RLA developer may handle it by forcing the secondary dial
projections to a non-NULL field using COALESCE, but that is not the best way to handle it. Using null indicators is.

What have you got against COALESCE? They certainly didn't add it to the language for RPG programmers <smile>.

Again, if no SQL access is used, value of understanding and use of NULL
diminishes, although it doesn't disappear.

Another reason I hate these discussions. Because I don't like NULLs, that means I don't understand them or SQL. Oh pshaw, Elvis <grin>.

What I think has not been mentioned yet in this thread is that most of the
other database platforms use SQL exclusively to access the database, so
developing understanding of these types of concepts could benefit developers whose retirement is not just around the corner by making them more versatile and marketable. Or simply able to help their non-i development team.

Please review my posts on the subject and find one place where I suggested that programmers should not understand NULL. On the contrary, I think programmers SHOULD understand NULL - that way they'll be more likely to use them appropriately. I think you yourself, Elvis, might benefit from reading Chris Date and Dr. Codd's writings on the subject to understand their views, which differ from your own.

This, though, is why I hate these threads. Because I don't like something means that I don't understand it. If you knew me, you'd know that's usually the opposite of the case; I don't form an opinion one way or the other about a topic until I understand it pretty well.

I use SQL every single day. I find it indispensable for analyzing data relationships, for finding anomalies in real world data, and for providing quick answers to data-related questions. Still, I still find that business logic is better represented in RPG than in SQL, and I find RLA to be easier to write, document, and extend. But if you go back through this list, you'll find that I'm one of the top posters when it comes to answering SQL questions. So I'd say you would be wrong to imply that I don't understand SQL because I don't like NULLs.

Enough for this morning... off to work...

Joe