@Override
public void visit(Function function) {
// all aggregate functions (SUM, AVG, COUNT, MAX, MIN) have only one parameter (Expression)
// although COUNT(*) has no parameters
// EXTRACT_YEAR has one parameter
// if you change this method, NameProjectVisitor.visit(Function) has to be changed as well
ExpressionList params = function.getParameters();
int numParams = 0;
if (params != null) {
params.accept(this);
// in order to determine the size
List<Expression> listParams = params.getExpressions();
numParams = listParams.size();
}
List<ValueExpression> expressions = new ArrayList<ValueExpression>();
for (int i = 0; i < numParams; i++) {
expressions.add(_exprStack.pop());
}
Collections.reverse(expressions); // at the stack top is the lastly added VE
String fnName = function.getName();
if (fnName.equalsIgnoreCase("EXTRACT_YEAR")) {
if (numParams != 1) {
throw new RuntimeException("EXTRACT_YEAR function has exactly one parameter!");
}
ValueExpression expr = expressions.get(0);
ValueExpression ve = new IntegerYearFromDate(expr);
_exprStack.push(ve);
}
}
public SelectOperator getSelectOperator() {
if (_predStack.size() != 1) {
throw new RuntimeException(
"After WhereVisitor is done, it should contain one predicate exactly!");
}
return new SelectOperator(_predStack.peek());
}
@Override
public void visit(Division dvsn) {
visitBinaryOperation(dvsn);
ValueExpression right = _exprStack.pop();
ValueExpression left = _exprStack.pop();
ValueExpression division = new plan_runner.expressions.Division(left, right);
_exprStack.push(division);
}
@Override
public void visit(NotEqualsTo net) {
visitBinaryOperation(net);
ValueExpression right = _exprStack.pop();
ValueExpression left = _exprStack.pop();
ComparisonPredicate cp = new ComparisonPredicate(ComparisonPredicate.NONEQUAL_OP, left, right);
_predStack.push(cp);
}
@Override
public void visit(MinorThan mt) {
visitBinaryOperation(mt);
ValueExpression right = _exprStack.pop();
ValueExpression left = _exprStack.pop();
ComparisonPredicate cp = new ComparisonPredicate(ComparisonPredicate.LESS_OP, left, right);
_predStack.push(cp);
}
@Override
public void visit(GreaterThanEquals gte) {
visitBinaryOperation(gte);
ValueExpression right = _exprStack.pop();
ValueExpression left = _exprStack.pop();
ComparisonPredicate cp = new ComparisonPredicate(ComparisonPredicate.NONLESS_OP, left, right);
_predStack.push(cp);
}
@Override
public void visit(LikeExpression le) {
visitBinaryOperation(le);
ValueExpression right = _exprStack.pop();
ValueExpression left = _exprStack.pop();
LikePredicate lp = new LikePredicate(left, right);
_predStack.push(lp);
}
@Override
public void visit(Subtraction s) {
visitBinaryOperation(s);
ValueExpression right = _exprStack.pop();
ValueExpression left = _exprStack.pop();
ValueExpression sub = new plan_runner.expressions.Subtraction(left, right);
_exprStack.push(sub);
}
/*
* Each of these operations create a Squall type, that's why so much similar code
*/
@Override
public void visit(Addition adtn) {
visitBinaryOperation(adtn);
ValueExpression right = _exprStack.pop();
ValueExpression left = _exprStack.pop();
ValueExpression add = new plan_runner.expressions.Addition(left, right);
_exprStack.push(add);
}
@Override
public void visit(Multiplication m) {
visitBinaryOperation(m);
ValueExpression right = _exprStack.pop();
ValueExpression left = _exprStack.pop();
ValueExpression mult = new plan_runner.expressions.Multiplication(left, right);
_exprStack.push(mult);
}
@Override
public void visit(OrExpression oe) {
visitBinaryOperation(oe);
Predicate right = _predStack.pop();
Predicate left = _predStack.pop();
Predicate or = new OrPredicate(left, right);
_predStack.push(or);
}
@Override
public void visit(AndExpression ae) {
visitBinaryOperation(ae);
Predicate right = _predStack.pop();
Predicate left = _predStack.pop();
Predicate and = new AndPredicate(left, right);
_predStack.push(and);
}
@Override
public void visit(Column column) {
// extract type for the column
TypeConversion tc = _schema.getType(ParserUtil.getFullSchemaColumnName(column, _tan));
// extract the position (index) of the required column
int position = _it.getColumnIndex(column, _affectedComponent);
ValueExpression ve = new ColumnReference(tc, position);
_exprStack.push(ve);
}
protected void pushToExprStack(ValueExpression ve) {
_exprStack.push(ve);
}
@Override
public void visit(LongValue lv) {
ValueExpression ve = new ValueSpecification(_lc, lv.getValue());
_exprStack.push(ve);
}
@Override
public void visit(StringValue sv) {
ValueExpression ve = new ValueSpecification(_sc, sv.getValue());
_exprStack.push(ve);
}
@Override
public void visit(DateValue dv) {
ValueExpression ve = new ValueSpecification(_dateConv, dv.getValue());
_exprStack.push(ve);
}
