Takes an expression subquery's result set and verifies that only
a single scalar value is being returned.
NOTE: A row with a single column containing null will be returned from
getNextRow() if the underlying subquery ResultSet is empty.
author: jerry
OnceResultSet(NoPutResultSet s, Activation a, GeneratedMethod emptyRowFun, int cardinalityCheck, int resultSetNumber, int subqueryNumber, int pointOfAttachment, double optimizerEstimatedRowCount, double optimizerEstimatedCost)
Method Summary
public void
close() If the result set has been opened,
close the open scan.
getTimeSpent(int type) Return the total amount of time spent in this ResultSet
Parameters: type - CURRENT_RESULTSET_ONLY - time spent only in this ResultSetENTIRE_RESULTSET_TREE - time spent in this ResultSet and below.
public OnceResultSet(NoPutResultSet s, Activation a, GeneratedMethod emptyRowFun, int cardinalityCheck, int resultSetNumber, int subqueryNumber, int pointOfAttachment, double optimizerEstimatedRowCount, double optimizerEstimatedCost)(Code)
Return the requested value computed from the next row.
exception: StandardException - thrown on failure.StandardException ScalarSubqueryCardinalityViolationThrown if scalar subquery returns more than 1 row.
Return the total amount of time spent in this ResultSet
Parameters: type - CURRENT_RESULTSET_ONLY - time spent only in this ResultSetENTIRE_RESULTSET_TREE - time spent in this ResultSet and below. long The total amount of time spent (in milliseconds).
open a scan on the table. scan parameters are evaluated
at each open, so there is probably some way of altering
their values...
exception: StandardException - thrown if cursor finished.
reopen a scan on the table. scan parameters are evaluated
at each open, so there is probably some way of altering
their values...
exception: StandardException - thrown if cursor finished.
Fields inherited from org.apache.derby.impl.sql.execute.NoPutResultSetImpl
