Is it possible to Execute 2 insert or
Update Statements using cfquery?
Most likely yes. But whether you can run multiple statements is determined by your database type and driver/connection settings. For example, when you create an MS SQL datasource, IIRC multiple statements are allowed by default. Whereas MySQL drivers often disable multiple statements by default. That is to help avoid sql injection. So in that case you must to enable multiple statements explicitly in your connection settings. Otherwise, you cannot use multiple statements. There are also some databases (usually desktop ones like MS Access) that do not support multiple statements at all. So I do not think there is a blanket answer to this question.
If the two insert/update statements are related, you should definitely use a cftransaction as Sam suggested. That ensures the statements are treated as a single unit: ie Either they all succeed or they all fail. So you are not left with partial or inconsistent data. In order to accomplish that, a single connection will be used for both queries in the transaction.
I think every time we call cfquery we
are opening new connection DB
As Sam mentioned, that depends on your settings and whether you are using cftransaction. If you enable Maintain Connections (under Datasource settings in the CF Administrator) CF will maintain a pool of open connections. So when you run a query, CF just grabs an open connection from the pool, rather than opening a new one each time. When using cftransaction, the same connection should be used for all queries. Regardless of whether Maintain Connections is enabled or not.