Reader with access database

Question

Hi,

I just want to know if my information are correct:

the reader with the sql or.. database can always access the reader.read() method but if there is no data found it retrieves 0 or null as result,

but with the access database if there is no data then the reader.read() is false and does not access the content written in reader.read()

which means in sql when I put
reader.read(){
//write a code

}

the reader accesses the code but retrieves null result if no data found but with the access database the reader does not even access the code if no data found right?