I dont think you need to use APIs for that. there are various other ways, one is ..
Use ADO (ex: by setting reference to microsoft activeX data object 2.5 library)
declare a connection object

'put a error handler
on error goto cnnErr
dim cnn As New ADODB.Connection
'if you are using ODBC / DSN based connection use following
cnn.open "dsn=dsnName;uid=username;pwd=thepassword;database=urdatabase"
'if you are using OLE DB / DSN less connection use following
cnn.open "driver={SQL Server};server=urServer;uid=username;pwd=thepassword;database=urdatabase"
cnnErr:
msgbox "unable to connect to database"

You can also check the state of the connection by state property of connection

if cnn.state=adstateClosed then
msgbox "could not open connection"
else ' i.e. adStateOpen
'connction is open
end if