LastIdentity.java

package net.sourceforge.mayfly.evaluation.command;

import net.sourceforge.mayfly.MayflyException;
import net.sourceforge.mayfly.MayflyResultSet;
import net.sourceforge.mayfly.datastore.Cell;
import net.sourceforge.mayfly.datastore.DataStore;
import net.sourceforge.mayfly.evaluation.Expression;
import net.sourceforge.mayfly.evaluation.ResultRow;
import net.sourceforge.mayfly.evaluation.ResultRows;
import net.sourceforge.mayfly.evaluation.expression.LastIdentityExpression;
import net.sourceforge.mayfly.evaluation.select.Evaluator;
import net.sourceforge.mayfly.evaluation.what.Selected;


public class LastIdentity extends Command {

    private static final String UPDATE_MESSAGE = 
        "SELECT is only available with query, not update";

    @Override
    public UpdateStore update(DataStore store, String currentSchema) {
        throw new MayflyException(UPDATE_MESSAGE);
    }
    
    @Override
    public MayflyResultSet select(
        Evaluator evaluator, Cell lastIdentity) {
        Expression expression = new LastIdentityExpression();
        return new MayflyResultSet(
            new Selected(expression), 
            new ResultRows(
                new ResultRow()
                    .with(
                        expression,
                        lastIdentity)));
    }

}