Natural join on Microsoft Access

Question

Hi,
I want to know how to implement a natual join on two tables from two separate databases on Microsoft Access upon J2SE1.4.1
Thank.

Answer 1

Thanks in advance!
On the Dept table, there are two fields: deptName
(primary key) and owes. The Dept table is on the Dept
database.
On the Empl table, there are two fields: emplName
(primary key) and deptName (foreign key). The Empl
table is on the Empl database.
I have created two System DSNs: Dept is for the Dept
database and the Empl is for the Empl database.I'm sure you have good reasons for the tables being in separate databases, but this would be more natural to have the two tables in a single database. Since they are not, my suggestion is to create a link in one of the databases pointing to the other database/table. Assuming that you want the Dept database to be the focal point, you can create the link using File / Get External Data / Link Table. Select ODBC Database(s) from Files of Type. You will see a list of all ODBC DSN's (probably under the machine data source tabl), select the employee database DSN, you will get a list of tables, select the employee table. You now have a schema that shows both the dept and empl tables in the dept database.
>
In my code:
Connection deptConn, emplConn = null;
String deptString, emplString = null;
Statement deptSQL, emplSQL = null;
ResultSet deptRes, emplRes = null ;
Class.forName(?sun.jdbc.odbc.JdbcOdbcDriver?);
deptConn = DriverManager.getConnection(?jdbc:odbc:Dept?);
emplConn = DriverManager.getConnection(?jdbc:odbc:Empl?);I'm not sure what the question marks are in this code (perhaps they used to be quotes)? I know very little about the specifics of J2EE, but this code perhaps should be something like this, where Dept is the name of the Department DSN that you setup previously :
            Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
            Connection con = DriverManager.getConnection("jdbc:odbc:Dept","","");>
deptSQL = deptConn.createStatement();
emplSQL = emplConn.createStatement();
deptString = ?select * from empl, dept?;
deptRes = dempSQL.executeQuery( deptString ) ;Here you would only need to do something like this:
deptSQL = deptConn.createStatement();
deptString = "select * from empl as E, dept  as D where E.deptName = D.deptName";
deptRes = deptSQL.executeQuery(deptString);Is this helping, or am I still confused?