JDBC adapter doubts

I am working JDBC sender.

I have Microsoft sql databse. I have to select ten fields from the database. There Is a field CurrentValue in the data structure, and it is the last field.

Every one hour, I have to select data from database. If the CurrentValue has not changed I don't have to pick data. There are two primary keys fr selecting the data. Employee name and employee number.

Is this possible with sql jdbc adapter?

Can this done by sql queerry in communication channel?

Any more inputs I need to ask?

Also telnet is disabled in my desktop, how may I check if the port given by the database guy is correct ? I want to make sure there is no firewall also

Please suggest some methods