Can we have one database for different programming languages, what would be the difficulty to club all solutions in a single business suite [on hold]

I am in chaos situation in deciding Programming language with database for different solutions. if i want to include all of application packages as a single solution then what would be the problem. Can any one suggest the best resolution. Example : Application 1 : Programming Language is php and database is MySQL. Application 2 : Programming Language is java and database is MySQL. Application 3 : Programming Language is dot net and database is MySQL.