// if inner==true, does inner Join else does leftOuter Join
private RecordSource _Join(RecordSource left, RecordSource right, bool inner)
{
bool requiresSorting = true;
bool ascending = true;
PairFilter filter = null;
if (inner) filter = new InnerJoin(TableColumnSeparator);
else filter = new LeftOuterJoin(TableColumnSeparator);
// T = TypeSort asked for, either Ascending or Descending
// Right
// !T T
// l !T sbT slT
// e
// f T srT X
// t
if (requiresSorting) {
if (!left.InternalSource.Sorting.IsSorted || left.InternalSource.Sorting.IsSortedAscending != ascending) {
left.SortReduce(ascending, false);
}
if (!right.InternalSource.Sorting.IsSorted || right.InternalSource.Sorting.IsSortedAscending != ascending) {
right.SortReduce(ascending, false);
}
}
RecordSource source2BoperatedOn = new RecordSource(this);
source2BoperatedOn.InternalSource = filter;
filter.AddInput(left.InternalSource);
filter.AddInput(right.InternalSource);
return source2BoperatedOn;
}
/// <summary>
/// Pair performs operations two input RecordSources, left and right. These are, for
/// example, CatLeftThenRight, SortedMerge, FilterLeftByRightKey.
/// </summary>
/// <param name="left">One of two RecordSources</param>
/// <param name="right">One of two RecordSources</param>
/// <param name="pairOperation">The operation to perform on the input sources</param>
/// <returns>A RecordSource for further processing</returns>
public RecordSource Pair(RecordSource left, RecordSource right, PairOperation pairOperation)
{
PairFilter filter = null;
bool requiresSorting = false; // not all pair operations require inputs sorted
bool ascending = true;
switch (pairOperation) {
case PairOperation.FilterLeftInRight:
filter = new FilterLeftByRightKey(true);
requiresSorting = true;
break;
case PairOperation.FilterLeftNotInRight:
filter = new FilterLeftByRightKey(false);
requiresSorting = true;
break;
case PairOperation.MergeAscend:
filter = new SortedMerge(true);
requiresSorting = true;
ascending = true;
break;
case PairOperation.MergeDescend:
filter = new SortedMerge(false);
requiresSorting = true;
ascending = false;
break;
case PairOperation.CatLeftThenRight:
filter = new CatLeftThenRight();
requiresSorting = false;
break;
}
// T = TypeSort asked for, either Ascending or Descending
// Right
// !T T
// l !T sbT slT
// e
// f T srT X
// t
if (requiresSorting) {
if (!left.InternalSource.Sorting.IsSorted || left.InternalSource.Sorting.IsSortedAscending != ascending) {
left.SortReduce(ascending, false);
}
if (!right.InternalSource.Sorting.IsSorted || right.InternalSource.Sorting.IsSortedAscending != ascending) {
right.SortReduce(ascending, false);
}
}
RecordSource source2BoperatedOn = new RecordSource(this);
source2BoperatedOn.InternalSource = filter;
filter.AddInput(left.InternalSource);
filter.AddInput(right.InternalSource);
return source2BoperatedOn;
}