// effects: Given a cell, determines the paths to which the paths in
// columns map to in the C-space and returns them. If some columns
// are not projected in the cell, or if the corresponding properties
// are not mapped into C-space, returns null
internal Set <EdmProperty> GetCSlotsForTableColumns(IEnumerable <MemberPath> columns)
{
var fieldNums = SQuery.GetProjectedPositions(columns);
if (fieldNums == null)
{
return(null);
}
// The fields are mapped -- see if they are mapped on the
// cSide and they correspond to the primary key of the
// entity set
var cSideMembers = new Set <EdmProperty>();
foreach (var fieldNum in fieldNums)
{
var projectedSlot = CQuery.ProjectedSlotAt(fieldNum);
var slot = projectedSlot as MemberProjectedSlot;
if (slot != null)
{
// We can call LastMember since columns do not map to
// extents or memberEnds. Can cast to EdmProperty since it
// cannot be an association end
cSideMembers.Add((EdmProperty)slot.MemberPath.LeafEdmMember);
}
else
{
return(null);
}
}
return(cSideMembers);
}
private void GenerateCellRelations(int cellNumber)
{
// Generate the view cell relation
var projectedSlots = new List <ViewCellSlot>();
// construct a ViewCellSlot for each slot
Debug.Assert(
CQuery.NumProjectedSlots == SQuery.NumProjectedSlots,
"Cell queries in cell have a different number of slots");
for (var i = 0; i < CQuery.NumProjectedSlots; i++)
{
var cSlot = CQuery.ProjectedSlotAt(i);
var sSlot = SQuery.ProjectedSlotAt(i);
Debug.Assert(cSlot != null, "Has cell query been normalized?");
Debug.Assert(sSlot != null, "Has cell query been normalized?");
// These slots better be MemberProjectedSlots. We do not have constants etc at this point.
Debug.Assert(cSlot is MemberProjectedSlot, "cSlot is expected to be MemberProjectedSlot");
Debug.Assert(sSlot is MemberProjectedSlot, "sSlot is expected to be MemberProjectedSlot");
var cJoinSlot = (MemberProjectedSlot)cSlot;
var sJoinSlot = (MemberProjectedSlot)sSlot;
var slot = new ViewCellSlot(i, cJoinSlot, sJoinSlot);
projectedSlots.Add(slot);
}
m_viewCellRelation = new ViewCellRelation(this, projectedSlots, cellNumber);
}