The significance of the Rs.Open Sql,conn,a,b's two A,B representatives

Sql

When you use ASP to make dynamic pages, when you bind a database, you always open the Recordset: Rs.Open Sql,conn,a,b (A and B for each numeric value), what exactly does this A and B mean? A:adopenforwardonly (=0) is read-only and the current data record can only be moved down adOpenStatic (=3) is read-only and the current data record is free to move adOpenKeyset (=1) can read and write, the current data record can be moved freely adOpenDynamic (=2) can read and write, the current data record can be moved freely, you can see the new record B:adlockreadonly (=1) default value for opening read-only records adLockPessimistic (=2) pessimistic lock adLockOptimistic (=3) optimistic lock adLockBatchOptimistic (=4) batch optimistic lock