At this point, jrs is an inside JOIN of the two RowSet
objects based on their EMP_ID
columns. The application can now browse the combined data as if it were browsing one single RowSet
object. Because jrs is itself a RowSet
object, an application can navigate or modify it using RowSet
methods.
jrs.first(); int employeeID = jrs.getInt(1); String employeeName = jrs.getString(2);
Note that because the SQL JOIN
must be enforced when an application adds a second or subsequent RowSet
object, there may be an initial degradation in performance while the JOIN
is being performed.
The following code fragment adds an additional CachedRowSet
object. In this case, the match column (EMP_ID
) is set when the CachedRowSet
object is added to the JoinRowSet
object.
ResultSet rs3 = stmt.executeQuery("SELECT * FROM 401K_CONTRIB"); CachedRowSet fourO1k = new CachedRowSetImpl(); four01k.populate(rs3); jrs.addRowSet(four01k, 1);
The JoinRowSet
object jrs now contains values from all three tables. The data in each row in four01k in which the value for the EMP_ID
column matches a value for the EMP_ID
column in jrs has been added to jrs.
JoinRowSet
MethodsJoinRowSet
interface supplies several methods for adding RowSet
objects and for getting information about the JoinRowSet
object. RowSet
objectsRowSet
object at a time or to add multiple RowSet
objects at one time. In either case, the methods may specify the match column for each RowSet
object being added. RowSet
objects in the JoinRowSet
object, and another method retrieves the RowSet
names. A third method retrieves either the SQL WHERE
clause used behind the scenes to form the JOIN
or a text description of what the WHERE
clause does. JOIN
JOIN
type, and five methods find out whether the JoinRowSet
object supports a given type. JoinRowSet
object
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