Tomcat does not connect to the database, but when I run it from within netbeans works perfectly

Tomcat does not connect to the database, but when I run it from within
netbeans works perfectly

I'm using Java + BlazeDS + MySQL + Flash Builder + EclipseLink (JPA 2.1) +
Tomcat 7 (Windows)
The problem is this, when I compile my application within Netbeans the
connection to the database works perfectly. But when I do a deploy
directly in tomcat with war file it does not access the database.
I tried with multiple versions of tomcat, including tomcat netbeans and it
did not work. Only works when I run the project from within Netbeans
I'm almost mad trying to solve it, someone has gone through this problem?
I really appreciate any help