probably depends on which database you're using. I've tried this with Microsoft SQL Server Management Studio and it creates and lays out the diagram. I can't really say if it meets your requirements but the express edition is free so it's always possible to try it out.

Tool for automatically generating and laying out an entity relationship diagram?
HOw do I access a .xls file and save it in a seperate folder in an ubuntu environment? 
I  found that I could do this to access " find . -type f -name '*.xls' " but how do I save it in a folder? I am new to ubuntu and any help would be appreciated ..
 thanks
