This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
Yes, that was numan's question... "What is wrong with this query?"
My question is, what is the query supposed to do? To me it looks like a four-way Cartesian product of four unrelated files. That wouldn't be a good idea so there isn't much point in trying to make it work.
I don't know. Normally to select data from several tables you would do some kind of a join. If you really want to do the four-way cartesian product then you might have to do something different.
For example if two tables had a column with the same name, you might not be able to use "Select *" in that case. You might have to specify the names of the columns you want, complete with prefix to indicate which table they were coming from.
However I still advise you to start with a reasonable query. Trying to learn SQL from bad ideas is not a good approach.