Sorry for my poor english

I'm new in the forum

I need some help about how can I connect a BD via WAN network?

You are going to have to provide a lot more information. eg

Do you have a specific database in mind?

What are you security requirements?

What kind of client are you going to have?

How much data is going to be sent/received by the client?

What kind of bandwidth is available between the client and the host?

Just for starters.