public override QueryNode VisitSelectQuery(SelectQuery query)
{
base.VisitSelectQuery(query);
RowBufferCalculator rowBufferCalculator = new RowBufferCalculator(query);
rowBufferCalculator.Calculate();
query.RowBufferCalculator = rowBufferCalculator;
return query;
}
public override QueryNode VisitSelectQuery(SelectQuery query)
{
base.VisitSelectQuery(query);
RowBufferCalculator rowBufferCalculator = new RowBufferCalculator(query);
rowBufferCalculator.Calculate();
query.RowBufferCalculator = rowBufferCalculator;
return(query);
}
public override QueryNode VisitSelectQuery(SelectQuery query)
{
// Calculate needed row buffers
RowBufferCalculator rowBufferCalculator = query.RowBufferCalculator;
// Emit FROM
if (query.TableReferences != null)
{
Visit(query.TableReferences);
}
else
{
ConstantScanAlgebraNode constantScanAlgebraNode = new ConstantScanAlgebraNode();
constantScanAlgebraNode.DefinedValues = new ComputedValueDefinition[0];
SetLastAlgebraNode(constantScanAlgebraNode);
}
// Emit WHERE
if (query.WhereClause != null)
{
FilterAlgebraNode filterAlgebraNode = new FilterAlgebraNode();
filterAlgebraNode.Input = GetLastAlgebraNode();
filterAlgebraNode.Predicate = query.WhereClause;
SetLastAlgebraNode(filterAlgebraNode);
}
// Emit GROUP BY
if (query.GroupByColumns != null || query.IsAggregated)
{
EmitComputeScalarIfNeeded(rowBufferCalculator.ComputedGroupColumns);
List <AggregatedValueDefinition> definedValues = new List <AggregatedValueDefinition>();
foreach (AggregateExpression aggregateDependency in query.AggregateDependencies)
{
definedValues.Add(aggregateDependency.ValueDefinition);
}
if (query.GroupByColumns != null)
{
SortAlgebraNode sortAlgebraNode = new SortAlgebraNode();
sortAlgebraNode.Input = GetLastAlgebraNode();
sortAlgebraNode.SortEntries = rowBufferCalculator.GroupColumns;
sortAlgebraNode.SortOrders = CreateAscendingSortOrders(sortAlgebraNode.SortEntries.Length);
SetLastAlgebraNode(sortAlgebraNode);
}
AggregateAlgebraNode algebraNode = new AggregateAlgebraNode();
algebraNode.Input = GetLastAlgebraNode();
algebraNode.DefinedValues = definedValues.ToArray();
algebraNode.Groups = rowBufferCalculator.GroupColumns;
SetLastAlgebraNode(algebraNode);
}
// Emit HAVING
if (query.HavingClause != null)
{
FilterAlgebraNode filterAlgebraNode = new FilterAlgebraNode();
filterAlgebraNode.Input = GetLastAlgebraNode();
filterAlgebraNode.Predicate = query.HavingClause;
SetLastAlgebraNode(filterAlgebraNode);
}
// Emit compute scalar to calculate expressions needed in SELECT and ORDER BY
EmitComputeScalarIfNeeded(rowBufferCalculator.ComputedSelectAndOrderColumns);
// Emit DISTINCT and ORDER BY
if (query.IsDistinct && query.OrderByColumns != null)
{
List <RowBufferEntry> sortEntries = new List <RowBufferEntry>();
List <SortOrder> sortOrderList = new List <SortOrder>();
for (int i = 0; i < query.OrderByColumns.Length; i++)
{
sortEntries.Add(rowBufferCalculator.OrderColumns[i]);
sortOrderList.Add(query.OrderByColumns[i].SortOrder);
}
foreach (RowBufferEntry selectColumn in rowBufferCalculator.SelectColumns)
{
bool selectColumnMustBeSorted = !sortEntries.Contains(selectColumn);
if (selectColumnMustBeSorted)
{
sortEntries.Add(selectColumn);
sortOrderList.Add(SortOrder.Ascending);
}
}
SortAlgebraNode sortAlgebraNode = new SortAlgebraNode();
sortAlgebraNode.Distinct = true;
sortAlgebraNode.Input = GetLastAlgebraNode();
sortAlgebraNode.SortEntries = sortEntries.ToArray();
sortAlgebraNode.SortOrders = sortOrderList.ToArray();
SetLastAlgebraNode(sortAlgebraNode);
}
else
{
if (query.IsDistinct)
{
SortAlgebraNode sortAlgebraNode = new SortAlgebraNode();
sortAlgebraNode.Distinct = true;
sortAlgebraNode.Input = GetLastAlgebraNode();
sortAlgebraNode.SortEntries = rowBufferCalculator.SelectColumns;
sortAlgebraNode.SortOrders = CreateAscendingSortOrders(sortAlgebraNode.SortEntries.Length);
SetLastAlgebraNode(sortAlgebraNode);
}
if (query.OrderByColumns != null)
{
List <SortOrder> sortOrderList = new List <SortOrder>();
foreach (OrderByColumn orderByColumn in query.OrderByColumns)
{
sortOrderList.Add(orderByColumn.SortOrder);
}
SortAlgebraNode sortAlgebraNode = new SortAlgebraNode();
sortAlgebraNode.Input = GetLastAlgebraNode();
sortAlgebraNode.SortEntries = rowBufferCalculator.OrderColumns;
sortAlgebraNode.SortOrders = sortOrderList.ToArray();
SetLastAlgebraNode(sortAlgebraNode);
}
}
// Emit TOP
if (query.TopClause != null)
{
TopAlgebraNode algebraNode = new TopAlgebraNode();
algebraNode.Input = GetLastAlgebraNode();
algebraNode.Limit = query.TopClause.Value;
if (query.TopClause.WithTies)
{
algebraNode.TieEntries = rowBufferCalculator.OrderColumns;
}
SetLastAlgebraNode(algebraNode);
}
// Emit select list
List <string> columnNames = new List <string>();
foreach (SelectColumn columnSource in query.SelectColumns)
{
if (columnSource.Alias != null)
{
columnNames.Add(columnSource.Alias.Text);
}
else
{
columnNames.Add(null);
}
}
ResultAlgebraNode resultAlgebraNode = new ResultAlgebraNode();
resultAlgebraNode.Input = GetLastAlgebraNode();
resultAlgebraNode.OutputList = rowBufferCalculator.SelectColumns;
resultAlgebraNode.ColumnNames = columnNames.ToArray();
SetLastAlgebraNode(resultAlgebraNode);
return(query);
}