A."server=Aptech;database=Exam;uid=bill;pwd=123456;" B."server=Aptech;database=Exam;integratedsecurity=sspi" C."server=.;database=Exam;uid=bill;pwd=123456" D."server=127.0.0.1;database=Exam;integratedsecurity=sspi"
A.OleDbConnection B.SqlConnection C.OdbcConnection D.Connection
A.ConnectionString B.DataSource C.UserInformation D.Provider