An error that occurs when a SELECT statement is first executed
prevents a ResultSet object from being opened on it. The same error
does not close the ResultSet if it occurs after the ResultSet has
been opened.
For example, a divide-by-zero error that happens while the executeQuery method
is called on a java.sql.Statement or java.sql.PreparedStatement throws
an exception and returns no result set at all, while if the same error happens
while the next method is called on a ResultSet object, it does
not cause the result set to be closed.
Errors can happen when a ResultSet is first being created
if the system partially executes the query before the first row is fetched.
This can happen on any query that uses more than one table and on queries
that use aggregates, GROUP BY, ORDER BY, DISTINCT, INTERSECT, EXCEPT, or UNION.
Closing a Statement causes all open ResultSet objects
on that statement to be closed as well.
The cursor name for the cursor of a ResultSet can be set
before the statement is executed. However, once it is executed, the cursor
name cannot be altered.
