@Override
public void visit(SelectExpressionItem item) {
ColumnParser columnParser = new ColumnParser();
item.getExpression().accept(columnParser);
if (columnParser.isSimple()) {
String columnName = columnParser.getColumnName();
simpleColumnNames.add(columnName);
aliases.put(columnName, StringUtils.strip(item.getAlias().getName(), "`").toUpperCase());
}
}
@Override
public void visit(SelectExpressionItem sei) {
_exprStack = new Stack<ValueExpression>();
_agg = null;
sei.getExpression().accept(this);
doneSingleItem();
}
@Override
public void visit(SelectExpressionItem selectExpressionItem) {
if (firstRun) {
if (selectExpressionItem.getAlias() != null) {
aliases.add(selectExpressionItem.getAlias().getName().toUpperCase());
}
} else {
if (selectExpressionItem.getAlias() == null) {
while (true) {
String alias = getNextAlias().toUpperCase();
if (!aliases.contains(alias)) {
aliases.add(alias);
selectExpressionItem.setAlias(new Alias(alias));
break;
}
}
}
}
}
@Override
public Object[] readOneTuple() {
// TODO Auto-generated method stub
Object[] temp = op.readOneTuple();
Evaluator eval = new Evaluator(schema, temp);
int index = 0;
if (temp == null) return null;
if (allColumns) return temp;
for (SelectExpressionItem e : toProject) {
try {
if (e.getExpression() instanceof Function) {
Expression x = new Column(null, e.getExpression().toString());
tuple[index] = eval.eval(x);
} else {
tuple[index] = eval.eval(e.getExpression());
}
} catch (SQLException e1) {
System.out.println("Exception in ProjectOperator.readOneTuple()");
}
index++;
}
return tuple;
}
@Override
public void visit(SelectExpressionItem selectExpressionItem) throws Exception {
selectExpressionItem.getExpression().accept(this);
}