DBMS: Which One To Learn?

I'm confused.. ..

IBM's DB2
Oracle
Microsoft's SQL Server
Sybase

Oracle is one of the most widely used DBMS in the world, so it may be a good idea to learn it.

>>> Oracle is one of the most widely used DBMS in the world

That is certainly true, but it is also outrageously expensive. If you want a budget introduction to db programming, use MS Access or Sybase SQL AnyWhere. Learn both ODBC and OLE db. Oracle, indeed all the big ones, also publish their own API's but these are non portable.

Oracle is one of the really big players, used widely with corporations. They have a personal Edition for free. That might be a nice start.

MySQL is beginning to take a significant part of the market share and I heard the US government is looking into switching to it (due to the cost benefit).
ORACLE is dominating right now, so I'd go for that.
Definitely look into MySQL though.

>>> They have a personal Edition for free.

I downloaded the free version, (in 20 seperate files because the whole thing was huge!), and I never got it to work.

Our DBA tested it once on his personal PC. He said it's running fine, but then, he's our DBA, he knows how to do stuff with Oracle ;)

I have to learn Oracle at school in about 8 months from now, but I would rather learn Microsoft SQL 2000 because it is compatible with the .NET Framework and it is reasonably affordable especially since you can acquire MSDN and get all their servers.

Either way, you will have to learn SQL. Make Oracle your priority DBMS to learn, then look into others. Oracle isn't the easiest thing to use (understatement!), but once you get a grip on it you'll be fine.