multiple workstations to one database

hi,

im developing a system where it'll be running accross about four workstations, these four are all connected to a database server. my question is in C# how and where do i synchronize database operations, for example deletion, adding, modifying and searching.

also.. is there any theoratical document that shows the difference between Java n C#, i search the net but only to get one that was on syntactical differences(by Dare Obasanjo). Any other reading materials?

thx !!