private SelectExpression ExtractOrders(SelectExpression sel, out List <OrderExpression> innerOrders)
{
if (sel.Top != null || (sel.OrderBy.Count == 0))
{
innerOrders = null;
return(sel);
}
else
{
ColumnGenerator cg = new ColumnGenerator(sel.Columns);
Dictionary <OrderExpression, ColumnDeclaration> newColumns = sel.OrderBy.ToDictionary(o => o, o => cg.NewColumn(o.Expression));
innerOrders = newColumns.Select(kvp => new OrderExpression(kvp.Key.OrderType, kvp.Value.GetReference(sel.Alias))).ToList();
return(new SelectExpression(sel.Alias, sel.IsDistinct, sel.Top, sel.Columns.Concat(newColumns.Values), sel.From, sel.Where, null, sel.GroupBy, sel.SelectOptions));
}
}
private ReadOnlyCollection <ColumnDeclaration> AnswerAndExpand(ReadOnlyCollection <ColumnDeclaration> columns, Alias currentAlias, Dictionary <ColumnExpression, Expression> askedColumns)
{
ColumnGenerator cg = new ColumnGenerator(columns);
foreach (var col in askedColumns.Keys.ToArray())
{
if (col.Alias == currentAlias)
{
Expression expr = columns.SingleEx(cd => (cd.Name ?? "-") == col.Name).Expression;
askedColumns[col] = expr is SqlConstantExpression? expr: col;
}
else
{
Expression expr = CurrentScope[col];
ColumnExpression colExp = expr as ColumnExpression;
if (colExp != null)
{
ColumnDeclaration cd = cg.Columns.FirstOrDefault(c => c.Expression.Equals(colExp));
if (cd == null)
{
cd = cg.MapColumn(colExp);
}
askedColumns[col] = new ColumnExpression(col.Type, currentAlias, cd.Name);
}
else
{
askedColumns[col] = expr;
}
}
}
if (columns.Count != cg.Columns.Count())
{
return(cg.Columns.ToReadOnly());
}
return(columns);
}
private ReadOnlyCollection<ColumnDeclaration> AnswerAndExpand(ReadOnlyCollection<ColumnDeclaration> columns, Alias currentAlias, Dictionary<ColumnExpression, Expression> askedColumns)
{
ColumnGenerator cg = new ColumnGenerator(columns);
foreach (var col in askedColumns.Keys.ToArray())
{
if (col.Alias == currentAlias)
{
Expression expr = columns.SingleEx(cd => (cd.Name ?? "-") == col.Name).Expression;
askedColumns[col] = expr.NodeType == (ExpressionType)DbExpressionType.SqlConstant? expr: col;
}
else
{
Expression expr = CurrentScope[col];
ColumnExpression colExp = expr as ColumnExpression;
if (colExp != null)
{
ColumnDeclaration cd = cg.Columns.FirstOrDefault(c => c.Expression.Equals(colExp));
if (cd == null)
{
cd = cg.MapColumn(colExp);
}
askedColumns[col] = new ColumnExpression(col.Type, currentAlias, cd.Name);
}
else
{
askedColumns[col] = expr;
}
}
}
if (columns.Count != cg.Columns.Count())
return cg.Columns.ToReadOnly();
return columns;
}
protected override Expression VisitProjection(ProjectionExpression proj)
{
if (currentSource == null)
{
currentSource = WithoutOrder(proj.Select);
Expression projector = this.Visit(proj.Projector);
if (projector != proj.Projector)
proj = new ProjectionExpression(proj.Select, projector, proj.UniqueFunction, proj.Type);
currentSource = null;
return proj;
}
else
{
HashSet<ColumnExpression> columns = ExternalColumnGatherer.Gatherer(proj, currentSource.Alias);
if (columns.Count == 0)
{
Expression projector = Visit(proj.Projector);
ConstantExpression key = Expression.Constant(0);
Type kvpType = typeof(KeyValuePair<,>).MakeGenericType(key.Type, projector.Type);
ConstructorInfo ciKVP = kvpType.GetConstructor(new[] { key.Type, projector.Type });
Type projType = proj.UniqueFunction == null ? typeof(IEnumerable<>).MakeGenericType(kvpType) : kvpType;
var childProj = new ProjectionExpression(proj.Select,
Expression.New(ciKVP, key, projector), proj.UniqueFunction, projType);
return new ChildProjectionExpression(childProj,
Expression.Constant(0), inMList, proj.Type, new LookupToken());
}
else
{
SelectExpression external;
IEnumerable<ColumnExpression> externalColumns;
if (!IsKey(currentSource, columns))
{
Alias aliasDistinct = aliasGenerator.GetUniqueAlias(currentSource.Alias.Name + "D");
ColumnGenerator generatorDistinct = new ColumnGenerator();
List<ColumnDeclaration> columnDistinct = columns.Select(ce => generatorDistinct.MapColumn(ce)).ToList();
external = new SelectExpression(aliasDistinct, true, null, columnDistinct, currentSource, null, null, null, 0);
Dictionary<ColumnExpression, ColumnExpression> distinctReplacements = columnDistinct.ToDictionary(
cd => (ColumnExpression)cd.Expression,
cd => cd.GetReference(aliasDistinct));
proj = (ProjectionExpression)ColumnReplacer.Replace(proj, distinctReplacements);
externalColumns = distinctReplacements.Values.ToHashSet();
}
else
{
external = currentSource;
externalColumns = columns;
}
ColumnGenerator generatorSM = new ColumnGenerator();
List<ColumnDeclaration> columnsSMExternal = externalColumns.Select(ce => generatorSM.MapColumn(ce)).ToList();
List<ColumnDeclaration> columnsSMInternal = proj.Select.Columns.Select(cd => generatorSM.MapColumn(cd.GetReference(proj.Select.Alias))).ToList();
List<OrderExpression> innerOrders;
SelectExpression @internal = ExtractOrders(proj.Select, out innerOrders);
Alias aliasSM = aliasGenerator.GetUniqueAlias(@internal.Alias.Name + "SM");
SelectExpression selectMany = new SelectExpression(aliasSM, false, null, columnsSMExternal.Concat(columnsSMInternal),
new JoinExpression(JoinType.CrossApply,
external,
@internal, null), null, innerOrders, null, 0);
SelectExpression old = currentSource;
currentSource = WithoutOrder(selectMany);
var selectManyReplacements = selectMany.Columns.ToDictionary(
cd => (ColumnExpression)cd.Expression,
cd => cd.GetReference(aliasSM));
Expression projector = ColumnReplacer.Replace(proj.Projector, selectManyReplacements);
projector = Visit(projector);
currentSource = old;
Expression key = TupleReflection.TupleChainConstructor(columnsSMExternal.Select(cd => cd.GetReference(aliasSM).Nullify()));
Type kvpType = typeof(KeyValuePair<,>).MakeGenericType(key.Type, projector.Type);
ConstructorInfo ciKVP = kvpType.GetConstructor(new[] { key.Type, projector.Type });
Type projType = proj.UniqueFunction == null ? typeof(IEnumerable<>).MakeGenericType(kvpType) : kvpType;
var childProj = new ProjectionExpression(selectMany,
Expression.New(ciKVP, key, projector), proj.UniqueFunction, projType);
return new ChildProjectionExpression(childProj,
TupleReflection.TupleChainConstructor(columns.Select(a => a.Nullify())), inMList, proj.Type, new LookupToken());
}
}
}
private SelectExpression ExtractOrders(SelectExpression sel, out List<OrderExpression> innerOrders)
{
if (sel.Top != null || (sel.OrderBy == null || sel.OrderBy.Count == 0))
{
innerOrders = null;
return sel;
}
else
{
ColumnGenerator cg = new ColumnGenerator(sel.Columns);
Dictionary<OrderExpression, ColumnDeclaration> newColumns = sel.OrderBy.ToDictionary(o => o, o => cg.NewColumn(o.Expression));
innerOrders = newColumns.Select(kvp => new OrderExpression(kvp.Key.OrderType, kvp.Value.GetReference(sel.Alias))).ToList();
return new SelectExpression(sel.Alias, sel.IsDistinct, sel.Top, sel.Columns.Concat(newColumns.Values), sel.From, sel.Where, null, sel.GroupBy, sel.SelectOptions);
}
}
protected internal override Expression VisitProjection(ProjectionExpression proj)
{
if (currentSource == null)
{
currentSource = WithoutOrder(proj.Select);
Expression projector = this.Visit(proj.Projector);
if (projector != proj.Projector)
{
proj = new ProjectionExpression(proj.Select, projector, proj.UniqueFunction, proj.Type);
}
currentSource = null;
return(proj);
}
else
{
HashSet <ColumnExpression> columns = ExternalColumnGatherer.Gatherer(proj, currentSource.Alias);
if (columns.Count == 0)
{
Expression projector = Visit(proj.Projector);
ConstantExpression key = Expression.Constant(0);
Type kvpType = typeof(KeyValuePair <,>).MakeGenericType(key.Type, projector.Type);
ConstructorInfo ciKVP = kvpType.GetConstructor(new[] { key.Type, projector.Type });
Type projType = proj.UniqueFunction == null ? typeof(IEnumerable <>).MakeGenericType(kvpType) : kvpType;
var childProj = new ProjectionExpression(proj.Select,
Expression.New(ciKVP, key, projector), proj.UniqueFunction, projType);
return(new ChildProjectionExpression(childProj,
Expression.Constant(0), inMList != null, inMList ?? proj.Type, new LookupToken()));
}
else
{
SelectExpression external;
IEnumerable <ColumnExpression> externalColumns;
if (!IsKey(currentSource, columns))
{
Alias aliasDistinct = aliasGenerator.GetUniqueAlias(currentSource.Alias.Name + "D");
ColumnGenerator generatorDistinct = new ColumnGenerator();
List <ColumnDeclaration> columnDistinct = columns.Select(ce => generatorDistinct.MapColumn(ce)).ToList();
external = new SelectExpression(aliasDistinct, true, null, columnDistinct, currentSource, null, null, null, 0);
Dictionary <ColumnExpression, ColumnExpression> distinctReplacements = columnDistinct.ToDictionary(
cd => (ColumnExpression)cd.Expression,
cd => cd.GetReference(aliasDistinct));
proj = (ProjectionExpression)ColumnReplacer.Replace(proj, distinctReplacements);
externalColumns = distinctReplacements.Values.ToHashSet();
}
else
{
external = currentSource;
externalColumns = columns;
}
ColumnGenerator generatorSM = new ColumnGenerator();
List <ColumnDeclaration> columnsSMExternal = externalColumns.Select(ce => generatorSM.MapColumn(ce)).ToList();
List <ColumnDeclaration> columnsSMInternal = proj.Select.Columns.Select(cd => generatorSM.MapColumn(cd.GetReference(proj.Select.Alias))).ToList();
List <OrderExpression> innerOrders;
SelectExpression @internal = ExtractOrders(proj.Select, out innerOrders);
Alias aliasSM = aliasGenerator.GetUniqueAlias(@internal.Alias.Name + "SM");
SelectExpression selectMany = new SelectExpression(aliasSM, false, null, columnsSMExternal.Concat(columnsSMInternal),
new JoinExpression(JoinType.CrossApply,
external,
@internal, null), null, innerOrders, null, 0);
SelectExpression old = currentSource;
currentSource = WithoutOrder(selectMany);
var selectManyReplacements = selectMany.Columns.ToDictionary(
cd => (ColumnExpression)cd.Expression,
cd => cd.GetReference(aliasSM));
Expression projector = ColumnReplacer.Replace(proj.Projector, selectManyReplacements);
projector = Visit(projector);
currentSource = old;
Expression key = TupleReflection.TupleChainConstructor(columnsSMExternal.Select(cd => cd.GetReference(aliasSM).Nullify()));
Type kvpType = typeof(KeyValuePair <,>).MakeGenericType(key.Type, projector.Type);
ConstructorInfo ciKVP = kvpType.GetConstructor(new[] { key.Type, projector.Type });
Type projType = proj.UniqueFunction == null ? typeof(IEnumerable <>).MakeGenericType(kvpType) : kvpType;
var childProj = new ProjectionExpression(selectMany,
Expression.New(ciKVP, key, projector), proj.UniqueFunction, projType);
return(new ChildProjectionExpression(childProj,
TupleReflection.TupleChainConstructor(columns.Select(a => a.Nullify())), inMList != null, inMList ?? proj.Type, new LookupToken()));
}
}
}
protected internal override Expression VisitSelect(SelectExpression select)
{
bool isOuterMost = select == outerMostSelect;
if (select.IsOrderAlsoByKeys || select.HasIndex || select.Top != null && hasProjectionInProjector)
{
if (gatheredKeys == null)
{
gatheredKeys = new List <ColumnExpression>();
}
}
List <ColumnExpression>?savedKeys = null;
if (gatheredKeys != null && (select.IsDistinct || select.GroupBy.HasItems() || select.IsAllAggregates))
{
savedKeys = gatheredKeys.ToList();
}
if ((AggregateFinder.GetAggregates(select.Columns)?.Any(a => a.AggregateFunction.OrderMatters()) ?? false) && select.From is SelectExpression from)
{
var oldOuterMostSelect = outerMostSelect;
outerMostSelect = from;
select = (SelectExpression)base.VisitSelect(select);
outerMostSelect = oldOuterMostSelect;
}
else
{
select = (SelectExpression)base.VisitSelect(select);
}
if (savedKeys != null)
{
gatheredKeys = savedKeys;
}
List <ColumnDeclaration>?newColumns = null;
if (select.GroupBy.HasItems())
{
gatheredOrderings = null;
if (gatheredKeys != null)
{
ColumnGenerator cg = new ColumnGenerator(select.Columns);
var newKeys = new List <ColumnDeclaration>();
foreach (var ge in select.GroupBy)
{
var cd = cg.Columns.NotNull().FirstOrDefault(a => DbExpressionComparer.AreEqual(a.Expression, ge));
if (cd != null)
{
newKeys.Add(cd);
}
else
{
newKeys.Add(cg.NewColumn(ge));
}
}
if (cg.Columns.Count() != select.Columns.Count)
{
newColumns = cg.Columns.NotNull().ToList();
}
gatheredKeys.AddRange(newKeys.Select(cd => new ColumnExpression(cd.Expression.Type, select.Alias, cd.Name)));
}
}
if (select.IsAllAggregates)
{
if (gatheredKeys != null)
{
gatheredKeys.AddRange(select.Columns.Select(cd => new ColumnExpression(cd.Expression.Type, select.Alias, cd.Name)));
}
}
if (select.IsDistinct)
{
gatheredOrderings = null;
if (gatheredKeys != null)
{
gatheredKeys.AddRange(select.Columns.Select(cd => cd.GetReference(select.Alias)));
}
}
if (select.IsReverse && !gatheredOrderings.IsNullOrEmpty())
{
gatheredOrderings = gatheredOrderings.Select(o => new OrderExpression(
o.OrderType == OrderType.Ascending ? OrderType.Descending : OrderType.Ascending,
o.Expression)).ToReadOnly();
}
if (select.OrderBy.Count > 0)
{
this.PrependOrderings(select.OrderBy);
}
ReadOnlyCollection <OrderExpression>?orderings = null;
if (isOuterMost && !IsCountSumOrAvg(select) || select.Top != null)
{
AppendKeys();
orderings = gatheredOrderings;
gatheredOrderings = null;
}
if (AreEqual(select.OrderBy, orderings) && !select.IsReverse && newColumns == null)
{
return(select);
}
return(new SelectExpression(select.Alias, select.IsDistinct, select.Top, (IEnumerable <ColumnDeclaration>?)newColumns ?? select.Columns,
select.From, select.Where, orderings, select.GroupBy, select.SelectOptions & ~SelectOptions.Reverse));
}
protected override Expression VisitSelect(SelectExpression select)
{
bool isOuterMost = select == outerMostSelect;
if (select.IsOrderAlsoByKeys || select.HasIndex || select.Top != null && hasProjectionInProjector)
{
if (gatheredKeys == null)
gatheredKeys = new List<ColumnExpression>();
}
List<ColumnExpression> saveKeys = null;
if (gatheredKeys != null && (select.IsDistinct || select.GroupBy.HasItems()))
saveKeys = gatheredKeys.ToList();
select = (SelectExpression)base.VisitSelect(select);
if (saveKeys != null)
gatheredKeys = saveKeys;
List<ColumnDeclaration> newColumns = null;
if (select.GroupBy.HasItems())
{
gatheredOrderings = null;
if (gatheredKeys != null)
{
ColumnGenerator cg = new ColumnGenerator(select.Columns);
var newKeys = new List<ColumnDeclaration>();
foreach (var ge in select.GroupBy)
{
var cd = cg.Columns.FirstOrDefault(a => DbExpressionComparer.AreEqual(a.Expression, ge));
if (cd != null)
newKeys.Add(cd);
else
newKeys.Add(cg.NewColumn(ge));
}
if (cg.Columns.Count() != select.Columns.Count)
newColumns = cg.Columns.ToList();
gatheredKeys.AddRange(newKeys.Select(cd => new ColumnExpression(cd.Expression.Type, select.Alias, cd.Name)));
}
}
if (select.IsDistinct)
{
gatheredOrderings = null;
if (gatheredKeys != null)
{
gatheredKeys.AddRange(select.Columns.Select(cd => cd.GetReference(select.Alias)));
}
}
if (select.IsReverse && !gatheredOrderings.IsNullOrEmpty())
gatheredOrderings = gatheredOrderings.Select(o => new OrderExpression(
o.OrderType == OrderType.Ascending ? OrderType.Descending : OrderType.Ascending,
o.Expression)).ToReadOnly();
if (select.OrderBy != null && select.OrderBy.Count > 0)
this.PrependOrderings(select.OrderBy);
ReadOnlyCollection<OrderExpression> orderings = null;
if (isOuterMost && !IsCountSumOrAvg(select) || select.Top != null)
{
AppendKeys();
orderings = gatheredOrderings;
gatheredOrderings = null;
}
if (AreEqual(select.OrderBy, orderings) && !select.IsReverse && newColumns == null)
return select;
return new SelectExpression(select.Alias, select.IsDistinct, select.Top, (IEnumerable<ColumnDeclaration>)newColumns ?? select.Columns,
select.From, select.Where, orderings, select.GroupBy, select.SelectOptions & ~SelectOptions.Reverse);
}
