public override void Enumerate(IMemberCompletionAcceptor acceptor)
{
if (acceptor == null)
throw ExceptionBuilder.ArgumentNull("acceptor");
// Report all columns accessible by the table ref.
TableRefBinding tableRefBinding = new TableRefBinding(null, _tableBinding, _correlationName);
foreach (ColumnBinding columnBinding in _tableBinding.Columns)
{
ColumnRefBinding columnRefBinding = new ColumnRefBinding(tableRefBinding, columnBinding);
acceptor.AcceptColumnRef(columnRefBinding);
}
// Now contribute any methods accessible by the row type.
IMethodProvider methodProvider = _scope.DataContext.MetadataContext.MethodProviders[_tableBinding.RowType];
if (methodProvider != null)
{
MethodBinding[] methods = methodProvider.GetMethods(_tableBinding.RowType);
foreach (MethodBinding methodBinding in methods)
acceptor.AcceptMethod(methodBinding);
}
}
public MetaInfo(ColumnRefBinding[] columnDependencies,
TableRefBinding[] tableDependencies,
bool containsSingleRowSubselects,
bool containsExistenceSubselects)
{
_columnDependencies = columnDependencies;
_tableDependencies = tableDependencies;
_containsSingleRowSubselects = containsSingleRowSubselects;
_containsExistenceSubselects = containsExistenceSubselects;
}
private static JoinOrder GetBestJoinOrder(TableRefBinding[] tables, JoinCondition[] joinConditions, ICollection<ExpressionNode> andParts)
{
// Compute all join orders
JoinOrderGenerator generator = new JoinOrderGenerator(joinConditions, tables);
JoinOrder[] allJoinOrders = generator.GenerateAll();
// Compute best join order
JoinOrder bestJoinOrder = GetBestJoinOrder(allJoinOrders, andParts, tables);
return bestJoinOrder;
}
private static ColumnRefBinding CreateRowColumnRefBinding(TableRefBinding tableRefBinding)
{
RowColumnBinding rowColumnBinding = new RowColumnBinding(tableRefBinding.TableBinding);
ColumnRefBinding rowColumnRefBinding = new ColumnRefBinding(tableRefBinding, rowColumnBinding);
RowBufferEntry rowColumnBufferEntry = new RowBufferEntry(rowColumnRefBinding.ColumnBinding.DataType);
rowColumnBufferEntry.Name = rowColumnRefBinding.TableRefBinding.Name;
ColumnValueDefinition rowColumnValueDefinition = new ColumnValueDefinition();
rowColumnValueDefinition.Target = rowColumnBufferEntry;
rowColumnValueDefinition.ColumnRefBinding = rowColumnRefBinding;
rowColumnRefBinding.ValueDefinition = rowColumnValueDefinition;
return rowColumnRefBinding;
}
private static JoinOrder GetBestJoinOrder(JoinOrder[] orders, ICollection<ExpressionNode> andParts, TableRefBinding[] tables)
{
// OK, now we try to find the best join order.
//
// To choose the best join order we will use a point system and score each possibility.
// The more points a possibility has the better it is.
//
// To ensure we exclude as much rows as possible and as early as possible
// we will use the count of conditions applicable to each combinations.
//
// A condition is said to be applicable if all referenced tables are already
// joined. For example if we have to join four tables T1, T2, T3, T4. Accordding to
// the join order T1 -> T2 -> T3 -> T4 the condition c is said to be applicable
// at join index 0 if it only references columns of table T1, at index 1 if it
// only references columns of tables T1 and T2 and so on.
// Determine minimal count of cross joins
int minCrossJoinCount = int.MaxValue;
for (int i = 0; i < orders.Length; i++)
{
int crossJoinCount = GetCrossJoinCount(orders[i]);
if (crossJoinCount < minCrossJoinCount)
minCrossJoinCount = crossJoinCount;
}
int[] points = new int[orders.Length];
for (int i = 0; i < orders.Length; i++)
{
points[i] = GetJoinOrderScore(orders[i], andParts, tables);
if (GetCrossJoinCount(orders[i]) > minCrossJoinCount)
{
// If the current join order uses more cross joins than
// the minimal one we reject this join order by setting
// its score to minus one.
points[i] = -1;
}
}
Array.Sort(points, orders);
JoinOrder bestJoinOrder = orders[orders.Length - 1];
return bestJoinOrder;
}
private static ColumnRefBinding CreateRowColumnRefBinding(TableRefBinding tableRefBinding)
{
RowColumnBinding rowColumnBinding = new RowColumnBinding(tableRefBinding.TableBinding);
ColumnRefBinding rowColumnRefBinding = new ColumnRefBinding(tableRefBinding, rowColumnBinding);
RowBufferEntry rowColumnBufferEntry = new RowBufferEntry(rowColumnRefBinding.ColumnBinding.DataType);
rowColumnBufferEntry.Name = rowColumnRefBinding.TableRefBinding.Name;
ColumnValueDefinition rowColumnValueDefinition = new ColumnValueDefinition();
rowColumnValueDefinition.Target = rowColumnBufferEntry;
rowColumnValueDefinition.ColumnRefBinding = rowColumnRefBinding;
rowColumnRefBinding.ValueDefinition = rowColumnValueDefinition;
return(rowColumnRefBinding);
}
void IErrorReporter.InvalidRowReference(SourceRange sourceRange, TableRefBinding derivedTableRef)
{
string message = String.Format(CultureInfo.CurrentCulture, Resources.InvalidRowReference, derivedTableRef.Name);
HandleError(sourceRange, ErrorId.InvalidRowReference, message);
}
void IErrorReporter.AmbiguousTableRef(SourceRange sourceRange, Identifier identifier, TableRefBinding[] candidates)
{
string message = String.Format(CultureInfo.CurrentCulture, Resources.AmbiguousTableRef, identifier, FormattingHelpers.FormatBindingList(candidates));
HandleError(sourceRange, ErrorId.AmbiguousTableRef, message);
}
public NullRejectionChecker(TableRefBinding nullableTableRefBinding)
{
_nullableTableRefBinding = nullableTableRefBinding;
}
public void AcceptRelation(TableRefBinding parentTableRef, TableRefBinding childTableRef, TableRelation relation)
{
}
private ColumnRefBinding ResolveColumnRef(TableRefBinding tableRef, SourceRange sourceRange, Identifier identifier)
{
QueryScope lookupScope = tableRef.Scope;
ColumnRefBinding[] candidates = lookupScope.FindColumnRef(tableRef, identifier);
if (candidates == null || candidates.Length == 0)
return null;
if (candidates.Length > 1)
ErrorReporter.AmbiguousColumnRef(sourceRange, identifier, candidates);
return candidates[0];
}
public void SwapSides()
{
ExpressionNode oldLeftExpression = _leftExpression;
TableRefBinding oldLeftTable = _leftTable;
_op = SwapJoinOperator(_op);
_leftExpression = _rightExpression;
_leftTable = _rightTable;
_rightExpression = oldLeftExpression;
_rightTable = oldLeftTable;
}
public override AlgebraNode VisitTableAlgebraNode(TableAlgebraNode node)
{
TableRefBinding oldTableRefBinding = node.TableRefBinding;
TableRefBinding newTableRefBinding = new TableRefBinding(oldTableRefBinding.Scope, oldTableRefBinding.TableBinding, oldTableRefBinding.Name);
List<ColumnValueDefinition> definedValues = new List<ColumnValueDefinition>();
for (int i = 0; i < newTableRefBinding.ColumnRefs.Length; i++)
{
definedValues.Add(newTableRefBinding.ColumnRefs[i].ValueDefinition);
RowBufferEntry oldRowBufferEntry = oldTableRefBinding.ColumnRefs[i].ValueDefinition.Target;
RowBufferEntry newRowBufferEntry = newTableRefBinding.ColumnRefs[i].ValueDefinition.Target;
_rowBufferMappings.Add(oldRowBufferEntry, newRowBufferEntry);
}
node.TableRefBinding = newTableRefBinding;
node.DefinedValues = definedValues.ToArray();
return node;
}
public void AcceptTableRef(TableRefBinding tableRef)
{
}
public JoinOrderGenerator(JoinCondition[] joinConditions, TableRefBinding[] tables)
{
_joinConditions = joinConditions;
_tables = tables;
}
public void AcceptTableRef(TableRefBinding tableRef)
{
Add(tableRef.Name, tableRef.GetFullName(), "TABLE REF", TABLE_REF_IMG_INDEX);
}
private static ExpressionNode ExtractConditionsApplicableToTable(IDictionary<RowBufferEntry, ColumnValueDefinition> introducedColumns, IList<ExpressionNode> conditionList, TableRefBinding tableRefBinding)
{
List<ExpressionNode> applicableConditionList = new List<ExpressionNode>();
for (int i = conditionList.Count - 1; i >= 0; i--)
{
ExpressionNode condition = conditionList[i];
RowBufferEntry[] rowBufferEntries = AstUtil.GetRowBufferEntryReferences(condition);
bool dependentOnOtherTable = false;
foreach (RowBufferEntry rowBufferEntry in rowBufferEntries)
{
ColumnValueDefinition columnValueDefinition;
if (introducedColumns.TryGetValue(rowBufferEntry, out columnValueDefinition))
{
if (columnValueDefinition.ColumnRefBinding.TableRefBinding != tableRefBinding)
{
dependentOnOtherTable = true;
break;
}
}
}
if (!dependentOnOtherTable)
{
conditionList.RemoveAt(i);
applicableConditionList.Add(condition);
}
}
if (applicableConditionList.Count == 0)
return null;
ExpressionNode[] applicableConditions = applicableConditionList.ToArray();
return AstUtil.CombineConditions(LogicalOperator.And, applicableConditions);
}
private void WriteTableRef(TableRefBinding tableRefBinding)
{
_xmlWriter.WriteAttributeString("table", tableRefBinding.TableBinding.Name);
_xmlWriter.WriteAttributeString("tableRef", tableRefBinding.Name);
}
public ColumnRefBinding(TableRefBinding tableRefBinding, ColumnBinding columnBinding)
{
_tableRefBinding = tableRefBinding;
_columnBinding = columnBinding;
}
private static AlgebraNode InstantiateCte(AlgebraNode algebrizedCte, CommonTableBinding commonTableBinding, TableRefBinding commonTableRefBinding)
{
// Replace row buffers to base tables by new ones. This must be done because a CTE could be referenced multiple times.
// Since same row buffer entries means that the underlying data will be stored in the same physical data slot this
// will lead to problems if, for example, two instances of the same CTE are joined together. Any join condition that
// operates on the same column will always compare data coming from the same join side (and therefor will always
// evaluate to true).
//
// Some notes on the implementation:
//
// 1. Note that just replacing references to row buffers of base tables in RowBufferExpression is not enough;
// instead they must also be replaced in output lists, defined value references (esp. ConcatAlgebraNode) etc.
// 2. Also note that although the QueryNodes are re-algebrized every time a CTE is references the expressions
// are still copied from the QueryNodes (instead of cloned). Therefore two algrebrized CTEs will share the same
// expression AST instances. That means that replacing the row buffers leads to failure.
// HACK: This is a workaround for issue 2. However,
// I am not quite sure how one should implement row buffer entry replacement without cloning the algebrized query.
algebrizedCte = (AlgebraNode) algebrizedCte.Clone();
CteTableDefinedValuesReinitializer cteTableDefinedValuesReinitializer = new CteTableDefinedValuesReinitializer();
cteTableDefinedValuesReinitializer.Visit(algebrizedCte);
RowBufferEntry[] outputList = algebrizedCte.OutputList;
int skipRecursionLevel = commonTableBinding.IsRecursive ? 1 : 0;
// Rename the query columns to the CTE columns
List<ComputedValueDefinition> definedValues = new List<ComputedValueDefinition>();
for (int i = 0; i < commonTableRefBinding.ColumnRefs.Length; i++)
{
RowBufferEntry targetRowBufferEntry = commonTableRefBinding.ColumnRefs[i].ValueDefinition.Target;
RowBufferEntry sourceRowBufferEntry = outputList[i + skipRecursionLevel];
ComputedValueDefinition definedValue = new ComputedValueDefinition();
definedValue.Target = targetRowBufferEntry;
definedValue.Expression = new RowBufferEntryExpression(sourceRowBufferEntry);
definedValues.Add(definedValue);
}
ComputeScalarAlgebraNode computeScalarAlgebraNode = new ComputeScalarAlgebraNode();
computeScalarAlgebraNode.Input = algebrizedCte;
computeScalarAlgebraNode.DefinedValues = definedValues.ToArray();
return computeScalarAlgebraNode;
}
void IErrorReporter.TableRefInaccessible(TableRefBinding tableRefBinding)
{
string message = String.Format(CultureInfo.CurrentCulture, Resources.TableRefInaccessible, tableRefBinding.Name, tableRefBinding.TableBinding.Name);
HandleError(ErrorId.TableRefInaccessible, message);
}
void IErrorReporter.UndeclaredColumn(SourceRange sourceRange, TableRefBinding tableRefBinding, Identifier identifier)
{
string message = String.Format(CultureInfo.CurrentCulture, Resources.UndeclaredColumn, tableRefBinding.Name, identifier);
HandleError(sourceRange, ErrorId.UndeclaredColumn, message);
}
public ColumnRefBinding(TableRefBinding tableRefBinding, ColumnBinding columnBinding)
{
_tableRefBinding = tableRefBinding;
_columnBinding = columnBinding;
}
public void AcceptRelation(TableRefBinding parentBinding, TableRefBinding childBinding, TableRelation relation)
{
ColumnBindingCollection parentColumns;
if (parentBinding.TableBinding == relation.ParentTable)
parentColumns = relation.ParentColumns;
else
parentColumns = relation.ChildColumns;
ColumnBindingCollection childColumns;
if (childBinding.TableBinding == relation.ChildTable)
childColumns = relation.ChildColumns;
else
childColumns = relation.ParentColumns;
// Item in member list:
// ~~~~~~~~~~~~~~~~~~~~
// parentRef(col1, col2) ---> childRef(col1, col2)
StringBuilder sb = new StringBuilder();
sb.Append(parentBinding.Name);
sb.Append(" (");
for (int i = 0; i < relation.ColumnCount; i++)
{
if (i > 0)
sb.Append(", ");
sb.Append(parentColumns[i].Name);
}
sb.Append(") ---> ");
sb.Append(childBinding.Name);
sb.Append(" (");
for (int i = 0; i < relation.ColumnCount; i++)
{
if (i > 0)
sb.Append(", ");
sb.Append(childColumns[i].Name);
}
sb.Append(")");
string name = sb.ToString();
sb.Length = 0;
// Description:
// ~~~~~~~~~~~~
// Relation <b>parentTable parentRef</b> ---> <b>ChildTable childRef</b> <br/>
// ON (parentRef.Col1 = childRef.Col1 AND parentRef.Col2 = childRef.Col2)
sb.Append("Relation <br/>");
sb.Append("<b>");
sb.Append(MaskIdentifier(parentBinding.TableBinding.Name));
sb.Append(" AS ");
sb.Append(MaskIdentifier(parentBinding.Name));
sb.Append("</b>");
sb.Append(" ---> ");
sb.Append("<b>");
sb.Append(MaskIdentifier(childBinding.TableBinding.Name));
sb.Append(" AS ");
sb.Append(MaskIdentifier(childBinding.Name));
sb.Append("</b><br/>ON (");
for (int i = 0; i < relation.ColumnCount; i++)
{
if (i > 0)
sb.Append(" AND ");
sb.Append(MaskIdentifier(parentBinding.Name));
sb.Append(".");
sb.Append(MaskIdentifier(parentColumns[i].Name));
sb.Append(" = ");
sb.Append(MaskIdentifier(childBinding.Name));
sb.Append(".");
sb.Append(MaskIdentifier(childColumns[i].Name));
}
sb.Append(")");
string description = sb.ToString();
sb.Length = 0;
// PreText:
// ~~~~~~~~
// parentAlias.Col1 = childAlias.Col1 AND parentAlias.Col2 = childAlias.Col2
for (int i = 0; i < relation.ColumnCount; i++)
{
if (i > 0)
sb.Append(" AND ");
sb.Append(MaskIdentifier(parentBinding.Name));
sb.Append(".");
sb.Append(MaskIdentifier(parentColumns[i].Name));
sb.Append(" = ");
sb.Append(MaskIdentifier(childBinding.Name));
sb.Append(".");
sb.Append(MaskIdentifier(childColumns[i].Name));
}
string preText = sb.ToString();
sb.Length = 0;
IntelliPromptMemberListItem item = new IntelliPromptMemberListItem(name, RELATION_IMG_INDEX, description, preText, String.Empty);
_members.Add(item);
}
private static int GetJoinOrderScore(JoinOrder joinOder, ICollection<ExpressionNode> andParts, TableRefBinding[] tables)
{
int result = 0;
Dictionary<RowBufferEntry, ColumnValueDefinition> introducedColumns = GetIntroducedColumns(joinOder);
for (int joinIndex = 0; joinIndex < tables.Length; joinIndex++)
{
ExpressionNode[] applicableConditions = GetAndPartsApplicableToJoin(introducedColumns, joinOder, joinIndex, andParts, false);
result *= 2;
result += applicableConditions.Length;
if (joinOder.Joins[joinIndex].JoinCondition != null)
result += 1;
}
return result;
}
private void Join(TableRefBinding table, JoinCondition joinCondition)
{
_usedTableList.Add(table);
_usedJoinConditionList.Add(joinCondition);
if (_usedTableList.Count == _tables.Length)
{
// We have joined all tables, create the join order.
//
// First we create a list of the join conditions we used.
List<Join> joinList = new List<Join>();
for (int i = 0; i < _usedTableList.Count; i++)
{
TableRefBinding usedTable = _usedTableList[i];
JoinCondition usedJoinCondition = _usedJoinConditionList[i];
// The first entry will be null, since we do not join from anywhere
if (usedJoinCondition != null)
{
// Since we swapping the join sides according to the direction
// we are joining from we need to create a clone. The clone
// is a flat copy meaning that the tables and expressions
// themselves are not cloned.
usedJoinCondition = usedJoinCondition.Clone();
// If the right table is not the table we are joining to
// swap the join sides.
if (usedJoinCondition.RightTable != usedTable)
usedJoinCondition.SwapSides();
}
Join join = new Join();
join.JoinCondition = usedJoinCondition;
join.TableRefBinding = usedTable;
joinList.Add(join);
}
// Secondly and very important: We also have to create a list of all
// join conditions NOT used. Later theses conditions will be combined
// with the and-parts since they must also be checked.
List<ExpressionNode> unusedConditionList = new List<ExpressionNode>();
foreach (JoinCondition jc in _joinConditions)
{
if (!_usedJoinConditionList.Contains(jc))
unusedConditionList.Add(jc.ToExpression());
}
JoinOrder joinOrder = new JoinOrder();
joinOrder.Joins = joinList.ToArray();
joinOrder.UnusedConditions = unusedConditionList.ToArray();
_joinOrderList.Add(joinOrder);
}
else
{
// We are not yet finished with all tables. Find next table
// to join with.
bool hasJoin = false;
foreach (JoinCondition nextJoin in _joinConditions)
{
if (!_usedJoinConditionList.Contains(nextJoin))
{
TableRefBinding nextTable;
if (_usedTableList.Contains(nextJoin.LeftTable))
{
nextTable = nextJoin.RightTable;
}
else if (_usedTableList.Contains(nextJoin.RightTable))
{
nextTable = nextJoin.LeftTable;
}
else
{
continue;
}
if (_usedTableList.Contains(nextTable))
continue;
Join(nextTable, nextJoin);
hasJoin = true;
}
}
if (!hasJoin)
{
foreach (TableRefBinding t in _tables)
{
if (!_usedTableList.Contains(t))
Join(t, null);
}
}
}
_usedJoinConditionList.RemoveAt(_usedJoinConditionList.Count - 1);
_usedTableList.RemoveAt(_usedTableList.Count - 1);
}
private void AddTable(TableRefBinding table)
{
if (IsOuterScope(table.Scope) && !_tableBindingList.Contains(table))
_tableBindingList.Add(table);
}
