public CteQueryPart(CteInfo cteInfo)
{
CteInfo = cteInfo;
Columns = cteInfo.CteContentParts
.OfType <ISelectableQueryPart>()
.FirstOrDefault(e => !(e is JoinTableQueryPart))?
.Columns;
}
public LogicNode CreateSetOpPlan(CteInfo cteInfo, bool top = true)
{
if (top)
{
// traversal on top node is the time to examine the setop tree
Debug.Assert(!IsLeaf());
VerifySelection();
}
if (IsLeaf())
{
stmt_.cteInfo_ = cteInfo;
return(stmt_.CreatePlan());
}
else
{
var lplan = left_.CreateSetOpPlan(cteInfo, false);
var rplan = right_.CreateSetOpPlan(cteInfo, false);
LogicNode plan;
// try to reuse existing operators to implment because users may write
// SQL code like this and this helps reduce optimizer search space
//
switch (op_)
{
case "unionall":
// union all keeps all rows, including duplicates
plan = new LogicAppend(lplan, rplan, this);
break;
case "union":
// union collect rows from both sides, and remove duplicates
plan = new LogicAppend(lplan, rplan, this);
var groupby = new List <Expr>(first_.selection_.CloneList());
plan = new LogicAgg(plan, groupby, null, null);
break;
case "except":
// except keeps left rows not found in right
case "intersect":
// intersect keeps rows found in both sides
var filter = FilterHelper.MakeFullComparator(
left_.first_.selection_, right_.first_.selection_);
var join = new LogicJoin(lplan, rplan);
if (op_.Contains("except"))
{
join.type_ = JoinType.AntiSemi;
}
if (op_.Contains("intersect"))
{
join.type_ = JoinType.Semi;
}
var logfilter = new LogicFilter(join, filter);
groupby = new List <Expr>(first_.selection_.CloneList());
plan = new LogicAgg(logfilter, groupby, null, null);
break;
case "exceptall":
case "intersectall":
// the 'all' semantics is a bit confusing than intuition:
// {1,1,1} exceptall {1,1} => {1}
// {1,1,1} intersectall {1,1} => {1,1}
//
throw new NotImplementedException();
default:
throw new InvalidProgramException();
}
return(plan);
}
}
public ISelectableQueryPart AddCte(CteInfo cteInfo)
{
_cteInfos.Add(cteInfo);
return(new CteQueryPart(cteInfo));
}
