private void GatherUnionExpressions(SqlNode node, List <SqlExpression> exprs)
{
SqlUnion union = node as SqlUnion;
if (union != null)
{
this.GatherUnionExpressions(union.Left, exprs);
this.GatherUnionExpressions(union.Right, exprs);
}
else
{
SqlSelect sel = node as SqlSelect;
if (sel != null)
{
SqlAliasRef aref = sel.Selection as SqlAliasRef;
if (aref != null)
{
this.GatherUnionExpressions(aref.Alias.Node, exprs);
}
else
{
exprs.Add(sel.Selection);
}
}
}
}
internal override SqlExpression VisitAliasRef(SqlAliasRef aref)
{
SqlNode node = aref.Alias.Node;
if (node is SqlTable || node is SqlTableValuedFunctionCall)
{
return(aref);
}
SqlUnion union = node as SqlUnion;
if (union != null)
{
return(this.ExpandUnion(union));
}
SqlSelect ss = node as SqlSelect;
if (ss != null)
{
return(this.VisitExpression(ss.Selection));
}
SqlExpression exp = node as SqlExpression;
if (exp != null)
{
return(this.VisitExpression(exp));
}
throw Error.CouldNotHandleAliasRef(node.NodeType);
}
internal override SqlExpression VisitAliasRef(SqlAliasRef aref)
{
if (this.ingoreExternalRefs && !this.nodeMap.ContainsKey(aref.Alias))
{
return(aref);
}
return(new SqlAliasRef((SqlAlias)this.Visit(aref.Alias)));
}
protected override SqlSelect GenerateSkipTake(SqlSelect sequence, SqlExpression skipExp, SqlExpression takeExp)
{
//return base.GenerateSkipTake(sequence, skipExp, takeExp);
SqlSelect node = LockSelect(sequence);
var value2 = skipExp as SqlValue;
if ((skipExp == null) || ((value2 != null) && (((int)value2.Value) <= 0)))
{
skipExp = sql.ValueFromObject(0, dominatingExpression);
}
var alias = new SqlAlias(node);
var selection = new SqlAliasRef(alias);
if (UseConverterStrategy(ConverterStrategy.SkipWithRowNumber))
{
var col = new SqlColumn("ROW_NUMBER",
this.sql.RowNumber(new List <SqlOrderExpression>(),
this.dominatingExpression));
var expr = new SqlColumnRef(col);
node.Row.Columns.Add(col);
var select2 = new SqlSelect(selection, alias, this.dominatingExpression);
if (takeExp != null)
{
select2.Where = this.sql.Between(expr, this.sql.Add(skipExp, 1),
this.sql.Binary(SqlNodeType.Add,
(SqlExpression)SqlDuplicator.Copy(skipExp),
takeExp), this.dominatingExpression);
return(select2);
}
select2.Where = this.sql.Binary(SqlNodeType.GT, expr, skipExp);
return(select2);
}
if (!this.CanSkipOnSelection(node.Selection))
{
throw SqlClient.Error.SkipNotSupportedForSequenceTypes();
}
var visitor = new SingleTableQueryVisitor();
visitor.Visit(node);
if (!visitor.IsValid)
{
throw ALinq.SqlClient.Error.SkipRequiresSingleTableQueryWithPKs();
}
var select3 = (SqlSelect)SqlDuplicator.Copy(node);
select3.Top = skipExp;
var alias2 = new SqlAlias(select3);
var ref4 = new SqlAliasRef(alias2);
var select = new SqlSelect(ref4, alias2, this.dominatingExpression);
select.Where = this.sql.Binary(SqlNodeType.EQ2V, selection, ref4);
SqlSubSelect expression = this.sql.SubSelect(SqlNodeType.Exists, select);
var select6 = new SqlSelect(selection, alias, this.dominatingExpression);
select6.Where = this.sql.Unary(SqlNodeType.Not, expression, this.dominatingExpression);
select6.Top = takeExp;
return(select6);
}
internal override SqlExpression VisitAliasRef(SqlAliasRef aref)
{
SqlAlias alias = aref.Alias;
SqlAlias value;
if (_removedMap.TryGetValue(alias, out value))
{
throw Error.InvalidReferenceToRemovedAliasDuringDeflation();
}
return(aref);
}
internal override SqlExpression VisitAliasRef(SqlAliasRef aref)
{
if ((UnwrapSequences != null) && UnwrapSequences.Unwrap)
{
UnwrapSequences = new UnwrapStack(UnwrapSequences, false);
VisitAlias(aref.Alias);
UnwrapSequences = UnwrapSequences.Last;
return(aref);
}
VisitAlias(aref.Alias);
return(aref);
}
internal SqlSelect BuildDefaultQuery(MetaType rowType, bool allowDeferred, SqlLink link, Expression source) {
System.Diagnostics.Debug.Assert(rowType != null && rowType.Table != null);
if (rowType.HasInheritance && rowType.InheritanceRoot != rowType) {
// RowType is expected to be an inheritance root.
throw Error.ArgumentWrongValue("rowType");
}
SqlTable table = sql.Table(rowType.Table, rowType, source);
SqlAlias tableAlias = new SqlAlias(table);
SqlAliasRef tableAliasRef = new SqlAliasRef(tableAlias);
SqlExpression projection = this.BuildProjection(tableAliasRef, table.RowType, allowDeferred, link, source);
return new SqlSelect(projection, tableAlias, source);
}
internal override SqlExpression VisitAliasRef(SqlAliasRef aref)
{
SqlExpression result = base.VisitAliasRef(aref);
if (result != null && result == aref)
{
// reference to outer scope, don't propogate references to expressions or aliases
SqlAlias alias = aref.Alias;
SqlAlias newalias = new SqlAlias(new SqlNop(aref.ClrType, aref.SqlType, null));
return(new SqlAliasRef(newalias));
}
return(result);
}
internal override SqlExpression VisitAliasRef(SqlAliasRef aref)
{
if (this.UnwrapSequences != null && this.UnwrapSequences.Unwrap)
{
this.UnwrapSequences = new UnwrapStack(this.UnwrapSequences, false);
this.VisitAlias(aref.Alias);
this.UnwrapSequences = this.UnwrapSequences.Last;
}
else
{
this.VisitAlias(aref.Alias);
}
return(aref);
}
internal SqlSelect BuildDefaultQuery(MetaType rowType, bool allowDeferred, SqlLink link, Expression source)
{
System.Diagnostics.Debug.Assert(rowType != null && rowType.Table != null);
if (rowType.HasInheritance && rowType.InheritanceRoot != rowType)
{
// RowType is expected to be an inheritance root.
throw Error.ArgumentWrongValue("rowType");
}
SqlTable table = sql.Table(rowType.Table, rowType, source);
SqlAlias tableAlias = new SqlAlias(table);
SqlAliasRef tableAliasRef = new SqlAliasRef(tableAlias);
SqlExpression projection = this.BuildProjection(tableAliasRef, table.RowType, allowDeferred, link, source);
return(new SqlSelect(projection, tableAlias, source));
}
internal override SqlExpression VisitAliasRef(SqlAliasRef aref) {
SqlNode node = aref.Alias.Node;
if (node is SqlTable || node is SqlTableValuedFunctionCall) {
return aref;
}
SqlUnion union = node as SqlUnion;
if (union != null) {
return this.ExpandUnion(union);
}
SqlSelect ss = node as SqlSelect;
if (ss != null) {
return this.VisitExpression(ss.Selection);
}
SqlExpression exp = node as SqlExpression;
if (exp != null)
return this.VisitExpression(exp);
throw Error.CouldNotHandleAliasRef(node.NodeType);
}
private SqlSelect VisitOrderBy(Expression sequence, LambdaExpression expression, SqlOrderType orderType) {
if (IsGrouping(expression.Body.Type)) {
throw Error.GroupingNotSupportedAsOrderCriterion();
}
if (!this.typeProvider.From(expression.Body.Type).IsOrderable) {
throw Error.TypeCannotBeOrdered(expression.Body.Type);
}
SqlSelect select = this.LockSelect(this.VisitSequence(sequence));
if (select.Selection.NodeType != SqlNodeType.AliasRef || select.OrderBy.Count > 0) {
SqlAlias alias = new SqlAlias(select);
SqlAliasRef aref = new SqlAliasRef(alias);
select = new SqlSelect(aref, alias, this.dominatingExpression);
}
this.map[expression.Parameters[0]] = (SqlAliasRef)select.Selection;
SqlExpression expr = this.VisitExpression(expression.Body);
select.OrderBy.Add(new SqlOrderExpression(orderType, expr));
return select;
}
private SqlNode VisitUnion(Expression source1, Expression source2) {
SqlSelect left = this.VisitSequence(source1);
SqlSelect right = this.VisitSequence(source2);
SqlUnion union = new SqlUnion(left, right, false);
SqlAlias alias = new SqlAlias(union);
SqlAliasRef aref = new SqlAliasRef(alias);
SqlSelect result = new SqlSelect(aref, alias, this.dominatingExpression);
result.OrderingType = SqlOrderingType.Blocked;
return result;
}
private SqlNode VisitExcept(Expression source1, Expression source2) {
Type type = TypeSystem.GetElementType(source1.Type);
if (IsGrouping(type)) {
throw Error.ExceptNotSupportedForHierarchicalTypes();
}
SqlSelect select1 = this.LockSelect(this.VisitSequence(source1));
SqlSelect select2 = this.VisitSequence(source2);
SqlAlias alias1 = new SqlAlias(select1);
SqlAliasRef aref1 = new SqlAliasRef(alias1);
SqlAlias alias2 = new SqlAlias(select2);
SqlAliasRef aref2 = new SqlAliasRef(alias2);
SqlExpression any = this.GenerateQuantifier(alias2, sql.Binary(SqlNodeType.EQ2V, aref1, aref2), true);
SqlSelect result = new SqlSelect(aref1, alias1, select1.SourceExpression);
result.Where = sql.Unary(SqlNodeType.Not, any);
result.IsDistinct = true;
result.OrderingType = SqlOrderingType.Blocked;
return result;
}
private SqlSelect GenerateSkipTake(SqlSelect sequence, SqlExpression skipExp, SqlExpression takeExp) {
SqlSelect select = this.LockSelect(sequence);
// no skip?
if (skipExp == null) {
if (takeExp != null) {
select.Top = takeExp;
}
return select;
}
SqlAlias alias = new SqlAlias(select);
SqlAliasRef aref = new SqlAliasRef(alias);
if (this.UseConverterStrategy(ConverterStrategy.SkipWithRowNumber)) {
// use ROW_NUMBER() (preferred)
SqlColumn rowNumber = new SqlColumn("ROW_NUMBER", sql.RowNumber(new List<SqlOrderExpression>(), this.dominatingExpression));
SqlColumnRef rowNumberRef = new SqlColumnRef(rowNumber);
select.Row.Columns.Add(rowNumber);
SqlSelect final = new SqlSelect(aref, alias, this.dominatingExpression);
if (takeExp != null) {
// use BETWEEN for skip+take combo (much faster)
final.Where = sql.Between(
rowNumberRef,
sql.Add(skipExp, 1),
sql.Binary(SqlNodeType.Add, (SqlExpression)SqlDuplicator.Copy(skipExp), takeExp),
this.dominatingExpression
);
}
else {
final.Where = sql.Binary(SqlNodeType.GT, rowNumberRef, skipExp);
}
return final;
}
else {
// Ensure that the sequence contains elements that can be skipped
if (!CanSkipOnSelection(select.Selection)) {
throw Error.SkipNotSupportedForSequenceTypes();
}
// use NOT EXISTS
// Supported cases:
// - Entities
// - Projections that contain all PK columns
//
// .. where there sequence can be traced back to a:
// - Single-table query
// - Distinct
// - Except
// - Intersect
// - Union, where union.All == false
// Not supported: joins
// Sequence should also be ordered, but we can't test for it at this
// point in processing, and we won't know that we need to test it, later.
SingleTableQueryVisitor stqv = new SingleTableQueryVisitor();
stqv.Visit(select);
if (!stqv.IsValid) {
throw Error.SkipRequiresSingleTableQueryWithPKs();
}
SqlSelect dupsel = (SqlSelect)SqlDuplicator.Copy(select);
dupsel.Top = skipExp;
SqlAlias dupAlias = new SqlAlias(dupsel);
SqlAliasRef dupRef = new SqlAliasRef(dupAlias);
SqlSelect eqsel = new SqlSelect(dupRef, dupAlias, this.dominatingExpression);
eqsel.Where = sql.Binary(SqlNodeType.EQ2V, aref, dupRef);
SqlSubSelect ss = sql.SubSelect(SqlNodeType.Exists, eqsel);
SqlSelect final = new SqlSelect(aref, alias, this.dominatingExpression);
final.Where = sql.Unary(SqlNodeType.Not, ss, this.dominatingExpression);
final.Top = takeExp;
return final;
}
}
/// <summary>
/// Translate a call to a table valued function expression into a sql select.
/// </summary>
private SqlNode TranslateTableValuedFunction(MethodCallExpression mce, MetaFunction function) {
// translate method call into sql function call
List<SqlExpression> sqlParams = GetFunctionParameters(mce, function);
SqlTableValuedFunctionCall functionCall = sql.TableValuedFunctionCall(function.ResultRowTypes[0].InheritanceRoot, mce.Method.ReturnType, function.MappedName, sqlParams, mce);
SqlAlias alias = new SqlAlias(functionCall);
SqlAliasRef aref = new SqlAliasRef(alias);
// Build default projection
SqlExpression projection = this.translator.BuildProjection(aref, function.ResultRowTypes[0].InheritanceRoot, this.allowDeferred, null, mce);
SqlSelect select = new SqlSelect(projection, alias, mce);
return select;
}
private SqlNode VisitQuantifier(SqlSelect select, LambdaExpression lambda, bool isAny) {
SqlAlias alias = new SqlAlias(select);
SqlAliasRef aref = new SqlAliasRef(alias);
if (lambda != null) {
this.map[lambda.Parameters[0]] = aref;
}
SqlExpression cond = lambda != null ? this.VisitExpression(lambda.Body) : null;
return this.GenerateQuantifier(alias, cond, isAny);
}
protected override SqlSelect GenerateSkipTake(SqlSelect sequence, SqlExpression skipExp, SqlExpression takeExp)
{
if (skipExp == null)
{
return(base.GenerateSkipTake(sequence, skipExp, takeExp));
}
Debug.Assert(skipExp != null);
var skipCount = (int)((SqlValue)skipExp).Value;
var alias = new SqlAlias(sequence);
var selection = new SqlAliasRef(alias);
var select = new SqlSelect(selection, alias, dominatingExpression);
if (takeExp == null)
{
return(base.GenerateSkipTake(sequence, skipExp, takeExp));
}
var type = sequence.SourceExpression.Type;
if (type.IsGenericType)
{
var args = type.GetGenericArguments();
if (args.Length == 1)
{
var mappingTable = Services.Model.GetTable(args[0]);
if (mappingTable != null)
{
return(base.GenerateSkipTake(sequence, skipExp, takeExp));
}
}
}
var takeCount = (int)((SqlValue)takeExp).Value;
select.Top = sql.Value(typeof(int), typeProvider.From(typeof(int)), takeCount, false,
dominatingExpression);
sequence.Top = sql.Value(typeof(int), typeProvider.From(typeof(int)), takeCount + skipCount, false,
dominatingExpression);
var finder = new OrderByFinder();
var orderby = finder.GetOrderBy(sequence);
foreach (var item in orderby)
{
if (item.OrderType == SqlOrderType.Descending)
{
select.OrderBy.Add(new SqlOrderExpression(SqlOrderType.Ascending, orderby[0].Expression));
}
else
{
select.OrderBy.Add(new SqlOrderExpression(SqlOrderType.Descending, orderby[0].Expression));
}
}
alias = new SqlAlias(select);
selection = new SqlAliasRef(alias);
select = new SqlSelect(selection, alias, dominatingExpression);
foreach (var item in orderby)
{
select.OrderBy.Add(new SqlOrderExpression(item.OrderType, item.Expression));
}
return(select);
}
private SqlSelect VisitGroupJoin(Expression outerSequence, Expression innerSequence, LambdaExpression outerKeySelector, LambdaExpression innerKeySelector, LambdaExpression resultSelector) {
SqlSelect outerSelect = this.VisitSequence(outerSequence);
SqlSelect innerSelect = this.VisitSequence(innerSequence);
SqlAlias outerAlias = new SqlAlias(outerSelect);
SqlAliasRef outerRef = new SqlAliasRef(outerAlias);
SqlAlias innerAlias = new SqlAlias(innerSelect);
SqlAliasRef innerRef = new SqlAliasRef(innerAlias);
this.map[outerKeySelector.Parameters[0]] = outerRef;
SqlExpression outerKey = this.VisitExpression(outerKeySelector.Body);
this.map[innerKeySelector.Parameters[0]] = innerRef;
SqlExpression innerKey = this.VisitExpression(innerKeySelector.Body);
// make multiset
SqlExpression pred = sql.Binary(SqlNodeType.EQ, outerKey, innerKey);
SqlSelect select = new SqlSelect(innerRef, innerAlias, this.dominatingExpression);
select.Where = pred;
SqlSubSelect subquery = sql.SubSelect(SqlNodeType.Multiset, select);
// make outer ref & multiset for result-selector params
this.map[resultSelector.Parameters[0]] = outerRef;
this.dupMap[resultSelector.Parameters[1]] = subquery;
SqlExpression result = this.VisitExpression(resultSelector.Body);
return new SqlSelect(result, outerAlias, this.dominatingExpression);
}
internal override SqlExpression VisitAliasRef(SqlAliasRef aref) {
if (this.ingoreExternalRefs && !this.nodeMap.ContainsKey(aref.Alias)) {
return aref;
}
return new SqlAliasRef((SqlAlias)this.Visit(aref.Alias));
}
private SqlSelect CoerceToSequence(SqlNode node) {
SqlSelect select = node as SqlSelect;
if (select == null) {
if (node.NodeType == SqlNodeType.Value) {
SqlValue sv = (SqlValue)node;
// Check for ITables.
ITable t = sv.Value as ITable;
if (t != null) {
return this.CoerceToSequence(this.TranslateConstantTable(t, null));
}
// Check for IQueryable.
IQueryable query = sv.Value as IQueryable;
if (query != null) {
Expression fex = Funcletizer.Funcletize(query.Expression);
// IQueryables that return self-referencing Constant expressions cause infinite recursion
if (fex.NodeType != ExpressionType.Constant ||
((ConstantExpression)fex).Value != query) {
return this.VisitSequence(fex);
}
throw Error.IQueryableCannotReturnSelfReferencingConstantExpression();
}
throw Error.CapturedValuesCannotBeSequences();
}
else if (node.NodeType == SqlNodeType.Multiset || node.NodeType == SqlNodeType.Element) {
return ((SqlSubSelect)node).Select;
}
else if (node.NodeType == SqlNodeType.ClientArray) {
throw Error.ConstructedArraysNotSupported();
}
else if (node.NodeType == SqlNodeType.ClientParameter) {
throw Error.ParametersCannotBeSequences();
}
// this needs to be a sequence expression!
SqlExpression sqlExpr = (SqlExpression)node;
SqlAlias sa = new SqlAlias(sqlExpr);
SqlAliasRef aref = new SqlAliasRef(sa);
return new SqlSelect(aref, sa, this.dominatingExpression);
}
return select;
}
private SqlSelect VisitSelectMany(Expression sequence, LambdaExpression colSelector, LambdaExpression resultSelector) {
SqlSelect seqSelect = this.VisitSequence(sequence);
SqlAlias seqAlias = new SqlAlias(seqSelect);
SqlAliasRef seqRef = new SqlAliasRef(seqAlias);
this.map[colSelector.Parameters[0]] = seqRef;
SqlNode colSelectorNode = this.VisitSequence(colSelector.Body);
SqlAlias selAlias = new SqlAlias(colSelectorNode);
SqlAliasRef selRef = new SqlAliasRef(selAlias);
SqlJoin join = new SqlJoin(SqlJoinType.CrossApply, seqAlias, selAlias, null, this.dominatingExpression);
SqlExpression projection = selRef;
if (resultSelector != null) {
this.map[resultSelector.Parameters[0]] = seqRef;
this.map[resultSelector.Parameters[1]] = selRef;
projection = this.VisitExpression(resultSelector.Body);
}
return new SqlSelect(projection, join, this.dominatingExpression);
}
private SqlStatement VisitInsert(Expression item, LambdaExpression resultSelector) {
if (item == null) {
throw Error.ArgumentNull("item");
}
this.dominatingExpression = item;
MetaTable metaTable = this.services.Model.GetTable(item.Type);
Expression source = this.services.Context.GetTable(metaTable.RowType.Type).Expression;
MetaType itemMetaType = null;
SqlNew sqlItem = null;
// construct insert assignments from 'item' info
ConstantExpression conItem = item as ConstantExpression;
if (conItem == null) {
throw Error.InsertItemMustBeConstant();
}
if (conItem.Value == null) {
throw Error.ArgumentNull("item");
}
// construct insert based on constant value
List<SqlMemberAssign> bindings = new List<SqlMemberAssign>();
itemMetaType = metaTable.RowType.GetInheritanceType(conItem.Value.GetType());
SqlExpression sqlExprItem = sql.ValueFromObject(conItem.Value, true, source);
foreach (MetaDataMember mm in itemMetaType.PersistentDataMembers) {
if (!mm.IsAssociation && !mm.IsDbGenerated && !mm.IsVersion) {
bindings.Add(new SqlMemberAssign(mm.Member, sql.Member(sqlExprItem, mm.Member)));
}
}
ConstructorInfo cons = itemMetaType.Type.GetConstructor(Type.EmptyTypes);
System.Diagnostics.Debug.Assert(cons != null);
sqlItem = sql.New(itemMetaType, cons, null, null, bindings, item);
SqlTable tab = sql.Table(metaTable, metaTable.RowType, this.dominatingExpression);
SqlInsert sin = new SqlInsert(tab, sqlItem, item);
if (resultSelector == null) {
return sin;
}
else {
MetaDataMember id = itemMetaType.DBGeneratedIdentityMember;
bool isDbGenOnly = false;
if (id != null) {
isDbGenOnly = this.IsDbGeneratedKeyProjectionOnly(resultSelector.Body, id);
if (id.Type == typeof(Guid) && (this.converterStrategy & ConverterStrategy.CanOutputFromInsert) != 0) {
sin.OutputKey = new SqlColumn(id.Type, sql.Default(id), id.Name, id, null, this.dominatingExpression);
if (!isDbGenOnly) {
sin.OutputToLocal = true;
}
}
}
SqlSelect result = null;
SqlSelect preResult = null;
SqlAlias tableAlias = new SqlAlias(tab);
SqlAliasRef tableAliasRef = new SqlAliasRef(tableAlias);
System.Diagnostics.Debug.Assert(resultSelector.Parameters.Count == 1);
this.map.Add(resultSelector.Parameters[0], tableAliasRef);
SqlExpression projection = this.VisitExpression(resultSelector.Body);
// build select to return result
SqlExpression pred = null;
if (id != null) {
pred = sql.Binary(
SqlNodeType.EQ,
sql.Member(tableAliasRef, id.Member),
this.GetIdentityExpression(id, sin.OutputKey != null)
);
}
else {
SqlExpression itemExpression = this.VisitExpression(item);
pred = sql.Binary(SqlNodeType.EQ2V, tableAliasRef, itemExpression);
}
result = new SqlSelect(projection, tableAlias, resultSelector);
result.Where = pred;
// Since we're only projecting back a single generated key, we can
// optimize the query to a simple selection (e.g. SELECT @@IDENTITY)
// rather than selecting back from the table.
if (id != null && isDbGenOnly) {
if (sin.OutputKey == null) {
SqlExpression exp = this.GetIdentityExpression(id, false);
if (exp.ClrType != id.Type) {
ProviderType sqlType = sql.Default(id);
exp = sql.ConvertTo(id.Type, sqlType, exp);
}
// The result selector passed in was bound to the table -
// we need to rebind to the single result as an array projection
ParameterExpression p = Expression.Parameter(id.Type, "p");
Expression[] init = new Expression[1] { Expression.Convert(p, typeof(object)) };
NewArrayExpression arrExp = Expression.NewArrayInit(typeof(object), init);
LambdaExpression rs = Expression.Lambda(arrExp, p);
this.map.Add(p, exp);
SqlExpression proj = this.VisitExpression(rs.Body);
preResult = new SqlSelect(proj, null, rs);
}
else {
// case handled in formatter automatically
}
result.DoNotOutput = true;
}
// combine insert & result into block
SqlBlock block = new SqlBlock(this.dominatingExpression);
block.Statements.Add(sin);
if (preResult != null) {
block.Statements.Add(preResult);
}
block.Statements.Add(result);
return block;
}
}
internal virtual SqlExpression VisitAliasRef(SqlAliasRef aref) {
return aref;
}
internal override SqlExpression VisitAliasRef(SqlAliasRef aref) {
throw Error.UnexpectedNode(aref.NodeType);
}
private SqlNode VisitGroupBy(Expression sequence, LambdaExpression keyLambda, LambdaExpression elemLambda, LambdaExpression resultSelector) {
// Convert seq.Group(elem, key) into
//
// SELECT s.key, MULTISET(select s2.elem from seq AS s2 where s.key == s2.key)
// FROM seq AS s
//
// where key and elem can be either simple scalars or object constructions
//
SqlSelect seq = this.VisitSequence(sequence);
seq = this.LockSelect(seq);
SqlAlias seqAlias = new SqlAlias(seq);
SqlAliasRef seqAliasRef = new SqlAliasRef(seqAlias);
// evaluate the key expression relative to original sequence
this.map[keyLambda.Parameters[0]] = seqAliasRef;
SqlExpression keyExpr = this.VisitExpression(keyLambda.Body);
// make a duplicate of the original sequence to use as a foundation of our group multiset
SqlDuplicator sd = new SqlDuplicator();
SqlSelect selDup = (SqlSelect)sd.Duplicate(seq);
// rebind key in relative to the duplicate sequence
SqlAlias selDupAlias = new SqlAlias(selDup);
SqlAliasRef selDupRef = new SqlAliasRef(selDupAlias);
this.map[keyLambda.Parameters[0]] = selDupRef;
SqlExpression keyDup = this.VisitExpression(keyLambda.Body);
SqlExpression elemExpr = null;
SqlExpression elemOnGroupSource = null;
if (elemLambda != null) {
// evaluate element expression relative to the duplicate sequence
this.map[elemLambda.Parameters[0]] = selDupRef;
elemExpr = this.VisitExpression(elemLambda.Body);
// evaluate element expression relative to original sequence
this.map[elemLambda.Parameters[0]] = seqAliasRef;
elemOnGroupSource = this.VisitExpression(elemLambda.Body);
}
else {
// no elem expression supplied, so just use an alias ref to the duplicate sequence.
// this will resolve to whatever was being produced by the sequence
elemExpr = selDupRef;
elemOnGroupSource = seqAliasRef;
}
// Make a sub expression out of the key. This will allow a single definition of the
// expression to be shared at multiple points in the tree (via SqlSharedExpressionRef's)
SqlSharedExpression keySubExpr = new SqlSharedExpression(keyExpr);
keyExpr = new SqlSharedExpressionRef(keySubExpr);
// construct the select clause that picks out the elements (this may be redundant...)
SqlSelect selElem = new SqlSelect(elemExpr, selDupAlias, this.dominatingExpression);
selElem.Where = sql.Binary(SqlNodeType.EQ2V, keyExpr, keyDup);
// Finally, make the MULTISET node. this will be used as part of the final select
SqlSubSelect ss = sql.SubSelect(SqlNodeType.Multiset, selElem);
// add a layer to the original sequence before applying the actual group-by clause
SqlSelect gsel = new SqlSelect(new SqlSharedExpressionRef(keySubExpr), seqAlias, this.dominatingExpression);
gsel.GroupBy.Add(keySubExpr);
SqlAlias gselAlias = new SqlAlias(gsel);
SqlSelect result = null;
if (resultSelector != null) {
// Create final select to include construction of group multiset
// select new Grouping { Key = key, Group = Multiset(select elem from seq where match) } from ...
Type elementType = typeof(IGrouping<,>).MakeGenericType(keyExpr.ClrType, elemExpr.ClrType);
SqlExpression keyGroup = new SqlGrouping(elementType, this.typeProvider.From(elementType), keyExpr, ss, this.dominatingExpression);
SqlSelect keyGroupSel = new SqlSelect(keyGroup, gselAlias, this.dominatingExpression);
SqlAlias kgAlias = new SqlAlias(keyGroupSel);
SqlAliasRef kgAliasRef = new SqlAliasRef(kgAlias);
this.map[resultSelector.Parameters[0]] = sql.Member(kgAliasRef, elementType.GetProperty("Key"));
this.map[resultSelector.Parameters[1]] = kgAliasRef;
// remember the select that has the actual group (for optimizing aggregates later)
this.gmap[kgAliasRef] = new GroupInfo { SelectWithGroup = gsel, ElementOnGroupSource = elemOnGroupSource };
SqlExpression resultExpr = this.VisitExpression(resultSelector.Body);
result = new SqlSelect(resultExpr, kgAlias, this.dominatingExpression);
// remember the select that has the actual group (for optimizing aggregates later)
this.gmap[resultExpr] = new GroupInfo { SelectWithGroup = gsel, ElementOnGroupSource = elemOnGroupSource };
}
else {
// Create final select to include construction of group multiset
// select new Grouping { Key = key, Group = Multiset(select elem from seq where match) } from ...
Type elementType = typeof(IGrouping<,>).MakeGenericType(keyExpr.ClrType, elemExpr.ClrType);
SqlExpression resultExpr = new SqlGrouping(elementType, this.typeProvider.From(elementType), keyExpr, ss, this.dominatingExpression);
result = new SqlSelect(resultExpr, gselAlias, this.dominatingExpression);
// remember the select that has the actual group (for optimizing aggregates later)
this.gmap[resultExpr] = new GroupInfo { SelectWithGroup = gsel, ElementOnGroupSource = elemOnGroupSource };
}
return result;
}
internal override SqlExpression VisitAliasRef(SqlAliasRef aref)
{
throw Error.UnexpectedNode(aref.NodeType);
}
private SqlNode VisitAggregate(Expression sequence, LambdaExpression lambda, SqlNodeType aggType, Type returnType) {
// Convert seq.Agg(exp) into
//
// 1) SELECT Agg(exp) FROM seq
// 2) SELECT Agg1 FROM (SELECT Agg(exp) as Agg1 FROM group-seq GROUP BY ...)
// 3) SCALAR(SELECT Agg(exp) FROM seq)
//
bool isCount = aggType == SqlNodeType.Count || aggType == SqlNodeType.LongCount;
SqlNode source = this.Visit(sequence);
SqlSelect select = this.CoerceToSequence(source);
SqlAlias alias = new SqlAlias(select);
SqlAliasRef aref = new SqlAliasRef(alias);
// If the sequence is of the form x.Select(expr).Agg() and the lambda for the aggregate is null,
// or is a no-op parameter expression (like u=>u), clone the group by selection lambda
// expression, and use for the aggregate.
// Final form should be x.Agg(expr)
MethodCallExpression mce = sequence as MethodCallExpression;
if (!outerNode && !isCount && (lambda == null || (lambda.Parameters.Count == 1 && lambda.Parameters[0] == lambda.Body)) &&
(mce != null) && IsSequenceOperatorCall(mce, "Select") && select.From is SqlAlias) {
LambdaExpression selectionLambda = GetLambda(mce.Arguments[1]);
lambda = Expression.Lambda(selectionLambda.Type, selectionLambda.Body, selectionLambda.Parameters);
alias = (SqlAlias)select.From;
aref = new SqlAliasRef(alias);
}
if (lambda != null && !TypeSystem.IsSimpleType(lambda.Body.Type)) {
throw Error.CannotAggregateType(lambda.Body.Type);
}
//Empty parameter aggregates are not allowed on anonymous types
//i.e. db.Customers.Select(c=>new{c.Age}).Max() instead it should be
// db.Customers.Select(c=>new{c.Age}).Max(c=>c.Age)
if (select.Selection.SqlType.IsRuntimeOnlyType && !IsGrouping(sequence.Type) && !isCount && lambda == null) {
throw Error.NonCountAggregateFunctionsAreNotValidOnProjections(aggType);
}
if (lambda != null)
this.map[lambda.Parameters[0]] = aref;
if (this.outerNode) {
// If this aggregate is basically the last/outer-most operator of the query
//
// produce SELECT Agg(exp) FROM seq
//
SqlExpression exp = (lambda != null) ? this.VisitExpression(lambda.Body) : null;
SqlExpression where = null;
if (isCount && exp != null) {
where = exp;
exp = null;
}
else if (exp == null && !isCount) {
exp = aref;
}
if (exp != null) {
// in case this contains another aggregate
exp = new SqlSimpleExpression(exp);
}
SqlSelect sel = new SqlSelect(
this.GetAggregate(aggType, returnType, exp),
alias,
this.dominatingExpression
);
sel.Where = where;
sel.OrderingType = SqlOrderingType.Never;
return sel;
}
else if (!isCount || lambda == null) {
// Look to optimize aggregate by pushing its evaluation down to the select node that has the
// actual group-by operator.
//
// Produce: SELECT Agg1 FROM (SELECT Agg(exp) as Agg1 FROM seq GROUP BY ...)
//
GroupInfo info = this.FindGroupInfo(source);
if (info != null) {
SqlExpression exp = null;
if (lambda != null) {
// evaluate expression relative to the group-by select node
this.map[lambda.Parameters[0]] = (SqlExpression)SqlDuplicator.Copy(info.ElementOnGroupSource);
exp = this.VisitExpression(lambda.Body);
} else if (!isCount) {
// support aggregates w/o an explicit selector specified
exp = info.ElementOnGroupSource;
}
if (exp != null) {
// in case this contains another aggregate
exp = new SqlSimpleExpression(exp);
}
SqlExpression agg = this.GetAggregate(aggType, returnType, exp);
SqlColumn c = new SqlColumn(agg.ClrType, agg.SqlType, null, null, agg, this.dominatingExpression);
info.SelectWithGroup.Row.Columns.Add(c);
return new SqlColumnRef(c);
}
}
// Otherwise, if we cannot optimize then fall back to generating a nested aggregate in a correlated sub query
//
// SCALAR(SELECT Agg(exp) FROM seq)
{
SqlExpression exp = (lambda != null) ? this.VisitExpression(lambda.Body) : null;
if (exp != null) {
// in case this contains another aggregate
exp = new SqlSimpleExpression(exp);
}
SqlSelect sel = new SqlSelect(
this.GetAggregate(aggType, returnType, isCount ? null : (lambda == null) ? aref : exp),
alias,
this.dominatingExpression
);
sel.Where = isCount ? exp : null;
return sql.SubSelect(SqlNodeType.ScalarSubSelect, sel);
}
}
internal SqlExpression TranslateEquals(SqlBinary expr)
{
System.Diagnostics.Debug.Assert(
expr.NodeType == SqlNodeType.EQ || expr.NodeType == SqlNodeType.NE ||
expr.NodeType == SqlNodeType.EQ2V || expr.NodeType == SqlNodeType.NE2V);
SqlExpression eLeft = expr.Left;
SqlExpression eRight = expr.Right;
if (eRight.NodeType == SqlNodeType.Element)
{
SqlSubSelect sub = (SqlSubSelect)eRight;
SqlAlias alias = new SqlAlias(sub.Select);
SqlAliasRef aref = new SqlAliasRef(alias);
SqlSelect select = new SqlSelect(aref, alias, expr.SourceExpression);
select.Where = sql.Binary(expr.NodeType, sql.DoNotVisitExpression(eLeft), aref);
return(sql.SubSelect(SqlNodeType.Exists, select));
}
else if (eLeft.NodeType == SqlNodeType.Element)
{
SqlSubSelect sub = (SqlSubSelect)eLeft;
SqlAlias alias = new SqlAlias(sub.Select);
SqlAliasRef aref = new SqlAliasRef(alias);
SqlSelect select = new SqlSelect(aref, alias, expr.SourceExpression);
select.Where = sql.Binary(expr.NodeType, sql.DoNotVisitExpression(eRight), aref);
return(sql.SubSelect(SqlNodeType.Exists, select));
}
MetaType mtLeft = TypeSource.GetSourceMetaType(eLeft, this.services.Model);
MetaType mtRight = TypeSource.GetSourceMetaType(eRight, this.services.Model);
if (eLeft.NodeType == SqlNodeType.TypeCase)
{
eLeft = BestIdentityNode((SqlTypeCase)eLeft);
}
if (eRight.NodeType == SqlNodeType.TypeCase)
{
eRight = BestIdentityNode((SqlTypeCase)eRight);
}
if (mtLeft.IsEntity && mtRight.IsEntity && mtLeft.Table != mtRight.Table)
{
throw Error.CannotCompareItemsAssociatedWithDifferentTable();
}
// do simple or no translation for non-structural types
if (!mtLeft.IsEntity && !mtRight.IsEntity &&
(eLeft.NodeType != SqlNodeType.New || eLeft.SqlType.CanBeColumn) &&
(eRight.NodeType != SqlNodeType.New || eRight.SqlType.CanBeColumn))
{
if (expr.NodeType == SqlNodeType.EQ2V || expr.NodeType == SqlNodeType.NE2V)
{
return(this.TranslateEqualsOp(expr.NodeType, sql.DoNotVisitExpression(expr.Left), sql.DoNotVisitExpression(expr.Right), false));
}
return(expr);
}
// If the two types are not comparable, we return the predicate "1=0".
if ((mtLeft != mtRight) && (mtLeft.InheritanceRoot != mtRight.InheritanceRoot))
{
return(sql.Binary(SqlNodeType.EQ, sql.ValueFromObject(0, expr.SourceExpression), sql.ValueFromObject(1, expr.SourceExpression)));
}
List <SqlExpression> exprs1;
List <SqlExpression> exprs2;
SqlLink link1 = eLeft as SqlLink;
if (link1 != null && link1.Member.IsAssociation && link1.Member.Association.IsForeignKey)
{
exprs1 = link1.KeyExpressions;
}
else
{
exprs1 = this.GetIdentityExpressions(mtLeft, sql.DoNotVisitExpression(eLeft));
}
SqlLink link2 = eRight as SqlLink;
if (link2 != null && link2.Member.IsAssociation && link2.Member.Association.IsForeignKey)
{
exprs2 = link2.KeyExpressions;
}
else
{
exprs2 = this.GetIdentityExpressions(mtRight, sql.DoNotVisitExpression(eRight));
}
System.Diagnostics.Debug.Assert(exprs1.Count > 0);
System.Diagnostics.Debug.Assert(exprs2.Count > 0);
System.Diagnostics.Debug.Assert(exprs1.Count == exprs2.Count);
SqlExpression exp = null;
SqlNodeType eqKind = (expr.NodeType == SqlNodeType.EQ2V || expr.NodeType == SqlNodeType.NE2V) ? SqlNodeType.EQ2V : SqlNodeType.EQ;
for (int i = 0, n = exprs1.Count; i < n; i++)
{
SqlExpression eq = this.TranslateEqualsOp(eqKind, exprs1[i], exprs2[i], !mtLeft.IsEntity);
if (exp == null)
{
exp = eq;
}
else
{
exp = sql.Binary(SqlNodeType.And, exp, eq);
}
}
if (expr.NodeType == SqlNodeType.NE || expr.NodeType == SqlNodeType.NE2V)
{
exp = sql.Unary(SqlNodeType.Not, exp, exp.SourceExpression);
}
return(exp);
}
private SqlExpression GenerateQuantifier(SqlAlias alias, SqlExpression cond, bool isAny) {
SqlAliasRef aref = new SqlAliasRef(alias);
if (isAny) {
SqlSelect sel = new SqlSelect(aref, alias, this.dominatingExpression);
sel.Where = cond;
sel.OrderingType = SqlOrderingType.Never;
SqlSubSelect exists = sql.SubSelect(SqlNodeType.Exists, sel);
return exists;
}
else {
SqlSelect sel = new SqlSelect(aref, alias, this.dominatingExpression);
SqlSubSelect ss = sql.SubSelect(SqlNodeType.Exists, sel);
sel.Where = sql.Unary(SqlNodeType.Not2V, cond, this.dominatingExpression);
return sql.Unary(SqlNodeType.Not, ss, this.dominatingExpression);
}
}
internal override SqlExpression VisitAliasRef(SqlAliasRef aref) {
SqlAlias alias = aref.Alias;
SqlAlias value;
if (this.removedMap.TryGetValue(alias, out value)) {
throw Error.InvalidReferenceToRemovedAliasDuringDeflation();
}
return aref;
}
private SqlSelect LockSelect(SqlSelect sel) {
if (sel.Selection.NodeType != SqlNodeType.AliasRef ||
sel.Where != null ||
sel.OrderBy.Count > 0 ||
sel.GroupBy.Count > 0 ||
sel.Having != null ||
sel.Top != null ||
sel.OrderingType != SqlOrderingType.Default ||
sel.IsDistinct) {
SqlAlias alias = new SqlAlias(sel);
SqlAliasRef aref = new SqlAliasRef(alias);
return new SqlSelect(aref, alias, this.dominatingExpression);
}
return sel;
}
internal override SqlExpression VisitAliasRef(SqlAliasRef aref) {
return this.ExpandExpression(aref);
}
private SqlSelect VisitSelect(Expression sequence, LambdaExpression selector) {
SqlSelect source = this.VisitSequence(sequence);
SqlAlias alias = new SqlAlias(source);
SqlAliasRef aref = new SqlAliasRef(alias);
this.map[selector.Parameters[0]] = aref;
SqlNode project = this.Visit(selector.Body);
SqlSelect pselect = project as SqlSelect;
if (pselect != null) {
return new SqlSelect(sql.SubSelect(SqlNodeType.Multiset, pselect, selector.Body.Type), alias, this.dominatingExpression);
}
else if ((project.NodeType == SqlNodeType.Element || project.NodeType == SqlNodeType.ScalarSubSelect) &&
(this.converterStrategy & ConverterStrategy.CanUseOuterApply) != 0) {
SqlSubSelect sub = (SqlSubSelect)project;
SqlSelect inner = sub.Select;
SqlAlias innerAlias = new SqlAlias(inner);
SqlAliasRef innerRef = new SqlAliasRef(innerAlias);
if (project.NodeType == SqlNodeType.Element) {
inner.Selection = new SqlOptionalValue(
new SqlColumn(
"test",
sql.Unary(
SqlNodeType.OuterJoinedValue,
sql.Value(typeof(int?), this.typeProvider.From(typeof(int)), 1, false, this.dominatingExpression)
)
),
sql.Unary(SqlNodeType.OuterJoinedValue, inner.Selection)
);
}
else {
inner.Selection = sql.Unary(SqlNodeType.OuterJoinedValue, inner.Selection);
}
SqlJoin join = new SqlJoin(SqlJoinType.OuterApply, alias, innerAlias, null, this.dominatingExpression);
return new SqlSelect(innerRef, join, this.dominatingExpression);
}
else {
SqlExpression expr = project as SqlExpression;
if (expr != null) {
return new SqlSelect(expr, alias, this.dominatingExpression);
}
else {
throw Error.BadProjectionInSelect();
}
}
}
internal SqlExpression ConvertToFetchedExpression(SqlNode node) {
if (node == null) {
return null;
}
switch (node.NodeType) {
case SqlNodeType.OuterJoinedValue: {
SqlExpression o = ((SqlUnary)node).Operand;
SqlExpression e = this.ConvertLinks(o);
if (e == o) {
return (SqlExpression)node;
}
return e;
}
case SqlNodeType.ClientCase: {
// Need to recurse in case the object case has links.
SqlClientCase cc = (SqlClientCase)node;
List<SqlNode> fetchedValues = new List<SqlNode>();
bool allExprs = true;
foreach (SqlClientWhen when in cc.Whens) {
SqlNode fetchedValue = ConvertToFetchedExpression(when.Value);
allExprs = allExprs && (fetchedValue is SqlExpression);
fetchedValues.Add(fetchedValue);
}
if (allExprs) {
// All WHEN values are simple expressions (no sequences).
List<SqlExpression> matches = new List<SqlExpression>();
List<SqlExpression> values = new List<SqlExpression>();
for (int i = 0, c = fetchedValues.Count; i < c; ++i) {
SqlExpression fetchedValue = (SqlExpression)fetchedValues[i];
if (!cc.ClrType.IsAssignableFrom(fetchedValue.ClrType)) {
throw Error.DidNotExpectTypeChange(cc.ClrType, fetchedValue.ClrType);
}
matches.Add(cc.Whens[i].Match);
values.Add(fetchedValue);
}
node = sql.Case(cc.ClrType, cc.Expression, matches, values, cc.SourceExpression);
}
else {
node = SimulateCaseOfSequences(cc, fetchedValues);
}
break;
}
case SqlNodeType.TypeCase: {
SqlTypeCase tc = (SqlTypeCase)node;
List<SqlNode> fetchedValues = new List<SqlNode>();
foreach (SqlTypeCaseWhen when in tc.Whens) {
SqlNode fetchedValue = ConvertToFetchedExpression(when.TypeBinding);
fetchedValues.Add(fetchedValue);
}
for (int i = 0, c = fetchedValues.Count; i < c; ++i) {
SqlExpression fetchedValue = (SqlExpression)fetchedValues[i];
tc.Whens[i].TypeBinding = fetchedValue;
}
break;
}
case SqlNodeType.SearchedCase: {
SqlSearchedCase sc = (SqlSearchedCase)node;
foreach (SqlWhen when in sc.Whens) {
when.Match = this.ConvertToFetchedExpression(when.Match);
when.Value = this.ConvertToFetchedExpression(when.Value);
}
sc.Else = this.ConvertToFetchedExpression(sc.Else);
break;
}
case SqlNodeType.Link: {
SqlLink link = (SqlLink)node;
if (link.Expansion != null) {
return this.VisitLinkExpansion(link);
}
SqlExpression cached;
if (this.linkMap.TryGetValue(link.Id, out cached)) {
return this.VisitExpression(cached);
}
// translate link into expanded form
node = this.translator.TranslateLink(link, true);
// New nodes may have been produced because of Subquery.
// Prebind again for method-call and static treat handling.
node = binder.Prebind(node);
// Make it an expression.
node = this.ConvertToExpression(node);
// bind the translation
node = this.Visit(node);
// Check for element node, rewrite as sql apply.
if (this.currentSelect != null
&& node != null
&& node.NodeType == SqlNodeType.Element
&& link.Member.IsAssociation
&& this.binder.OptimizeLinkExpansions
) {
// if link in a non-nullable foreign key association then inner-join is okay to use (since it must always exist)
// otherwise use left-outer-join
SqlJoinType joinType = (link.Member.Association.IsForeignKey && !link.Member.Association.IsNullable)
? SqlJoinType.Inner : SqlJoinType.LeftOuter;
SqlSubSelect ss = (SqlSubSelect)node;
SqlExpression where = ss.Select.Where;
ss.Select.Where = null;
// form cross apply
SqlAlias sa = new SqlAlias(ss.Select);
if (joinType == SqlJoinType.Inner && this.IsOuterDependent(this.currentSelect.From, sa, where))
{
joinType = SqlJoinType.LeftOuter;
}
this.currentSelect.From = sql.MakeJoin(joinType, this.currentSelect.From, sa, where, ss.SourceExpression);
SqlExpression result = new SqlAliasRef(sa);
this.linkMap.Add(link.Id, result);
return this.VisitExpression(result);
}
}
break;
}
return (SqlExpression)node;
}
private SqlSelect VisitJoin(Expression outerSequence, Expression innerSequence, LambdaExpression outerKeySelector, LambdaExpression innerKeySelector, LambdaExpression resultSelector) {
SqlSelect outerSelect = this.VisitSequence(outerSequence);
SqlSelect innerSelect = this.VisitSequence(innerSequence);
SqlAlias outerAlias = new SqlAlias(outerSelect);
SqlAliasRef outerRef = new SqlAliasRef(outerAlias);
SqlAlias innerAlias = new SqlAlias(innerSelect);
SqlAliasRef innerRef = new SqlAliasRef(innerAlias);
this.map[outerKeySelector.Parameters[0]] = outerRef;
SqlExpression outerKey = this.VisitExpression(outerKeySelector.Body);
this.map[innerKeySelector.Parameters[0]] = innerRef;
SqlExpression innerKey = this.VisitExpression(innerKeySelector.Body);
this.map[resultSelector.Parameters[0]] = outerRef;
this.map[resultSelector.Parameters[1]] = innerRef;
SqlExpression result = this.VisitExpression(resultSelector.Body);
SqlExpression condition = sql.Binary(SqlNodeType.EQ, outerKey, innerKey);
SqlSelect select = null;
if ((this.converterStrategy & ConverterStrategy.CanUseJoinOn) != 0) {
SqlJoin join = new SqlJoin(SqlJoinType.Inner, outerAlias, innerAlias, condition, this.dominatingExpression);
select = new SqlSelect(result, join, this.dominatingExpression);
} else {
SqlJoin join = new SqlJoin(SqlJoinType.Cross, outerAlias, innerAlias, null, this.dominatingExpression);
select = new SqlSelect(result, join, this.dominatingExpression);
select.Where = condition;
}
return select;
}
/// <summary>
/// Given a ClientCase and a list of sequence (one for each case), construct a structure
/// that is equivalent to a CASE of SELECTs. To accomplish this we use UNION ALL and attach
/// a WHERE clause which will pick the SELECT that matches the discriminator in the Client Case.
/// </summary>
private SqlSelect SimulateCaseOfSequences(SqlClientCase clientCase, List<SqlNode> sequences) {
/*
* There are two situations we may be in:
* (1) There is exactly one case alternative.
* Here, no where clause is needed.
* (2) There is more than case alternative.
* Here, each WHERE clause needs to be ANDed with [Disc]=D where D
* is the literal discriminanator value.
*/
if (sequences.Count == 1) {
return (SqlSelect)sequences[0];
}
else {
SqlNode union = null;
SqlSelect sel = null;
int elseIndex = clientCase.Whens.Count - 1;
int elseCount = clientCase.Whens[elseIndex].Match == null ? 1 : 0;
SqlExpression elseFilter = null;
for (int i = 0; i < sequences.Count - elseCount; ++i) {
sel = (SqlSelect)sequences[i];
SqlExpression discriminatorPredicate = sql.Binary(SqlNodeType.EQ, clientCase.Expression, clientCase.Whens[i].Match);
sel.Where = sql.AndAccumulate(sel.Where, discriminatorPredicate);
elseFilter = sql.AndAccumulate(elseFilter, sql.Binary(SqlNodeType.NE, clientCase.Expression, clientCase.Whens[i].Match));
if (union == null) {
union = sel;
}
else {
union = new SqlUnion(sel, union, true /* Union All */);
}
}
// Handle 'else' if present.
if (elseCount == 1) {
sel = (SqlSelect)sequences[elseIndex];
sel.Where = sql.AndAccumulate(sel.Where, elseFilter);
if (union == null) {
union = sel;
}
else {
union = new SqlUnion(sel, union, true /* Union All */);
}
}
SqlAlias alias = new SqlAlias(union);
SqlAliasRef aref = new SqlAliasRef(alias);
return new SqlSelect(aref, alias, union.SourceExpression);
}
}
private SqlSelect VisitDefaultIfEmpty(Expression sequence) {
SqlSelect select = this.VisitSequence(sequence);
SqlAlias alias = new SqlAlias(select);
SqlAliasRef aliasRef = new SqlAliasRef(alias);
SqlExpression opt = new SqlOptionalValue(
new SqlColumn(
"test",
sql.Unary(SqlNodeType.OuterJoinedValue,
sql.Value(typeof(int?), this.typeProvider.From(typeof(int)), 1, false, this.dominatingExpression)
)
),
sql.Unary(SqlNodeType.OuterJoinedValue, aliasRef)
);
SqlSelect optSelect = new SqlSelect(opt, alias, this.dominatingExpression);
alias = new SqlAlias(optSelect);
aliasRef = new SqlAliasRef(alias);
SqlExpression litNull = sql.TypedLiteralNull(typeof(string), this.dominatingExpression);
SqlSelect selNull = new SqlSelect(litNull, null, this.dominatingExpression);
SqlAlias aliasNull = new SqlAlias(selNull);
SqlJoin join = new SqlJoin(SqlJoinType.OuterApply, aliasNull, alias, null, this.dominatingExpression);
return new SqlSelect(aliasRef, join, this.dominatingExpression);
}
private SqlNode AccessMember(SqlMember m, SqlExpression expo) {
SqlExpression exp = expo;
switch (exp.NodeType) {
case SqlNodeType.ClientCase: {
// Distribute into each case.
SqlClientCase sc = (SqlClientCase)exp;
Type newClrType = null;
List<SqlExpression> matches = new List<SqlExpression>();
List<SqlExpression> values = new List<SqlExpression>();
foreach (SqlClientWhen when in sc.Whens) {
SqlExpression newValue = (SqlExpression)AccessMember(m, when.Value);
if (newClrType == null) {
newClrType = newValue.ClrType;
}
else if (newClrType != newValue.ClrType) {
throw Error.ExpectedClrTypesToAgree(newClrType, newValue.ClrType);
}
matches.Add(when.Match);
values.Add(newValue);
}
SqlExpression result = sql.Case(newClrType, sc.Expression, matches, values, sc.SourceExpression);
return result;
}
case SqlNodeType.SimpleCase: {
// Distribute into each case.
SqlSimpleCase sc = (SqlSimpleCase)exp;
Type newClrType = null;
List<SqlExpression> newMatches = new List<SqlExpression>();
List<SqlExpression> newValues = new List<SqlExpression>();
foreach (SqlWhen when in sc.Whens) {
SqlExpression newValue = (SqlExpression)AccessMember(m, when.Value);
if (newClrType == null) {
newClrType = newValue.ClrType;
}
else if (newClrType != newValue.ClrType) {
throw Error.ExpectedClrTypesToAgree(newClrType, newValue.ClrType);
}
newMatches.Add(when.Match);
newValues.Add(newValue);
}
SqlExpression result = sql.Case(newClrType, sc.Expression, newMatches, newValues, sc.SourceExpression);
return result;
}
case SqlNodeType.SearchedCase: {
// Distribute into each case.
SqlSearchedCase sc = (SqlSearchedCase)exp;
List<SqlWhen> whens = new List<SqlWhen>(sc.Whens.Count);
foreach (SqlWhen when in sc.Whens) {
SqlExpression value = (SqlExpression)AccessMember(m, when.Value);
whens.Add(new SqlWhen(when.Match, value));
}
SqlExpression @else = (SqlExpression)AccessMember(m, sc.Else);
return sql.SearchedCase(whens.ToArray(), @else, sc.SourceExpression);
}
case SqlNodeType.TypeCase: {
// We don't allow derived types to map members to different database fields.
// Therefore, just pick the best SqlNew to call AccessMember on.
SqlTypeCase tc = (SqlTypeCase)exp;
// Find the best type binding for this member.
SqlNew tb = tc.Whens[0].TypeBinding as SqlNew;
foreach (SqlTypeCaseWhen when in tc.Whens) {
if (when.TypeBinding.NodeType == SqlNodeType.New) {
SqlNew sn = (SqlNew)when.TypeBinding;
if (m.Member.DeclaringType.IsAssignableFrom(sn.ClrType)) {
tb = sn;
break;
}
}
}
return AccessMember(m, tb);
}
case SqlNodeType.AliasRef: {
// convert alias.Member => column
SqlAliasRef aref = (SqlAliasRef)exp;
// if its a table, find the matching column
SqlTable tab = aref.Alias.Node as SqlTable;
if (tab != null) {
MetaDataMember mm = GetRequiredInheritanceDataMember(tab.RowType, m.Member);
System.Diagnostics.Debug.Assert(mm != null);
string name = mm.MappedName;
SqlColumn c = tab.Find(name);
if (c == null) {
ProviderType sqlType = sql.Default(mm);
c = new SqlColumn(m.ClrType, sqlType, name, mm, null, m.SourceExpression);
c.Alias = aref.Alias;
tab.Columns.Add(c);
}
return new SqlColumnRef(c);
}
// if it is a table valued function, find the matching result column
SqlTableValuedFunctionCall fc = aref.Alias.Node as SqlTableValuedFunctionCall;
if (fc != null) {
MetaDataMember mm = GetRequiredInheritanceDataMember(fc.RowType, m.Member);
System.Diagnostics.Debug.Assert(mm != null);
string name = mm.MappedName;
SqlColumn c = fc.Find(name);
if (c == null) {
ProviderType sqlType = sql.Default(mm);
c = new SqlColumn(m.ClrType, sqlType, name, mm, null, m.SourceExpression);
c.Alias = aref.Alias;
fc.Columns.Add(c);
}
return new SqlColumnRef(c);
}
break;
}
case SqlNodeType.OptionalValue:
// convert option(exp).Member => exp.Member
return this.AccessMember(m, ((SqlOptionalValue)exp).Value);
case SqlNodeType.OuterJoinedValue: {
SqlNode n = this.AccessMember(m, ((SqlUnary)exp).Operand);
SqlExpression e = n as SqlExpression;
if (e != null) return sql.Unary(SqlNodeType.OuterJoinedValue, e);
return n;
}
case SqlNodeType.Lift:
return this.AccessMember(m, ((SqlLift)exp).Expression);
case SqlNodeType.UserRow: {
// convert UserRow.Member => UserColumn
SqlUserRow row = (SqlUserRow)exp;
SqlUserQuery suq = row.Query;
MetaDataMember mm = GetRequiredInheritanceDataMember(row.RowType, m.Member);
System.Diagnostics.Debug.Assert(mm != null);
string name = mm.MappedName;
SqlUserColumn c = suq.Find(name);
if (c == null) {
ProviderType sqlType = sql.Default(mm);
c = new SqlUserColumn(m.ClrType, sqlType, suq, name, mm.IsPrimaryKey, m.SourceExpression);
suq.Columns.Add(c);
}
return c;
}
case SqlNodeType.New: {
// convert (new {Member = expr}).Member => expr
SqlNew sn = (SqlNew)exp;
SqlExpression e = sn.Find(m.Member);
if (e != null) {
return e;
}
MetaDataMember mm = sn.MetaType.PersistentDataMembers.FirstOrDefault(p => p.Member == m.Member);
if (!sn.SqlType.CanBeColumn && mm != null) {
throw Error.MemberNotPartOfProjection(m.Member.DeclaringType, m.Member.Name);
}
break;
}
case SqlNodeType.Element:
case SqlNodeType.ScalarSubSelect: {
// convert Scalar/Element(select exp).Member => Scalar/Element(select exp.Member) / select exp.Member
SqlSubSelect sub = (SqlSubSelect)exp;
SqlAlias alias = new SqlAlias(sub.Select);
SqlAliasRef aref = new SqlAliasRef(alias);
SqlSelect saveSelect = this.currentSelect;
try {
SqlSelect newSelect = new SqlSelect(aref, alias, sub.SourceExpression);
this.currentSelect = newSelect;
SqlNode result = this.Visit(sql.Member(aref, m.Member));
SqlExpression rexp = result as SqlExpression;
if (rexp != null) {
// If the expression is still a Member after being visited, but it cannot be a column, then it cannot be collapsed
// into the SubSelect because we need to keep track of the fact that this member has to be accessed on the client.
// This must be done after the expression has been Visited above, because otherwise we don't have
// enough context to know if the member can be a column or not.
if (rexp.NodeType == SqlNodeType.Member && !SqlColumnizer.CanBeColumn(rexp)) {
// If the original member expression is an Element, optimize it by converting to an OuterApply if possible.
// We have to do this here because we are creating a new member expression based on it, and there are no
// subsequent visitors that will do this optimization.
if (this.canUseOuterApply && exp.NodeType == SqlNodeType.Element && this.currentSelect != null) {
// Reset the currentSelect since we are not going to use the previous SqlSelect that was created
this.currentSelect = saveSelect;
this.currentSelect.From = sql.MakeJoin(SqlJoinType.OuterApply, this.currentSelect.From, alias, null, sub.SourceExpression);
exp = this.VisitExpression(aref);
}
return sql.Member(exp, m.Member);
}
// Since we are going to make a SubSelect out of this member expression, we need to make
// sure it gets columnized before it gets to the PostBindDotNetConverter, otherwise only the
// entire SubSelect will be columnized as a whole. Subsequent columnization does not know how to handle
// any function calls that may be produced by the PostBindDotNetConverter, but we know how to handle it here.
newSelect.Selection = rexp;
newSelect.Selection = this.columnizer.ColumnizeSelection(newSelect.Selection);
newSelect.Selection = this.ConvertLinks(newSelect.Selection);
SqlNodeType subType = (rexp is SqlTypeCase || !rexp.SqlType.CanBeColumn) ? SqlNodeType.Element : SqlNodeType.ScalarSubSelect;
SqlSubSelect subSel = sql.SubSelect(subType, newSelect);
return this.FoldSubquery(subSel);
}
SqlSelect rselect = result as SqlSelect;
if (rselect != null) {
SqlAlias ralias = new SqlAlias(rselect);
SqlAliasRef rref = new SqlAliasRef(ralias);
newSelect.Selection = this.ConvertLinks(this.VisitExpression(rref));
newSelect.From = new SqlJoin(SqlJoinType.CrossApply, alias, ralias, null, m.SourceExpression);
return newSelect;
}
throw Error.UnexpectedNode(result.NodeType);
}
finally {
this.currentSelect = saveSelect;
}
}
case SqlNodeType.Value: {
SqlValue val = (SqlValue)exp;
if (val.Value == null) {
return sql.Value(m.ClrType, m.SqlType, null, val.IsClientSpecified, m.SourceExpression);
}
else if (m.Member is PropertyInfo) {
PropertyInfo p = (PropertyInfo)m.Member;
return sql.Value(m.ClrType, m.SqlType, p.GetValue(val.Value, null), val.IsClientSpecified, m.SourceExpression);
}
else {
FieldInfo f = (FieldInfo)m.Member;
return sql.Value(m.ClrType, m.SqlType, f.GetValue(val.Value), val.IsClientSpecified, m.SourceExpression);
}
}
case SqlNodeType.Grouping: {
SqlGrouping g = ((SqlGrouping)exp);
if (m.Member.Name == "Key") {
return g.Key;
}
break;
}
case SqlNodeType.ClientParameter: {
SqlClientParameter cp = (SqlClientParameter)exp;
// create new accessor including this member access
LambdaExpression accessor =
Expression.Lambda(
typeof(Func<,>).MakeGenericType(typeof(object[]), m.ClrType),
Expression.MakeMemberAccess(cp.Accessor.Body, m.Member),
cp.Accessor.Parameters
);
return new SqlClientParameter(m.ClrType, m.SqlType, accessor, cp.SourceExpression);
}
default:
break;
}
if (m.Expression == exp) {
return m;
}
else {
return sql.Member(exp, m.Member);
}
}
internal virtual SqlExpression VisitAliasRef(SqlAliasRef aref) {
return aref;
}
private SqlExpression FoldSubquery(SqlSubSelect ss) {
// convert ELEMENT(SELECT MULTISET(SELECT xxx FROM t1 WHERE p1) FROM t2 WHERE p2)
// into MULTISET(SELECT xxx FROM t2 CA (SELECT xxx FROM t1 WHERE p1) WHERE p2))
while (true) {
if (ss.NodeType == SqlNodeType.Element && ss.Select.Selection.NodeType == SqlNodeType.Multiset) {
SqlSubSelect msub = (SqlSubSelect)ss.Select.Selection;
SqlAlias alias = new SqlAlias(msub.Select);
SqlAliasRef aref = new SqlAliasRef(alias);
SqlSelect sel = ss.Select;
sel.Selection = this.ConvertLinks(this.VisitExpression(aref));
sel.From = new SqlJoin(SqlJoinType.CrossApply, sel.From, alias, null, ss.SourceExpression);
SqlSubSelect newss = sql.SubSelect(SqlNodeType.Multiset, sel, ss.ClrType);
ss = newss;
}
else if (ss.NodeType == SqlNodeType.Element && ss.Select.Selection.NodeType == SqlNodeType.Element) {
SqlSubSelect msub = (SqlSubSelect)ss.Select.Selection;
SqlAlias alias = new SqlAlias(msub.Select);
SqlAliasRef aref = new SqlAliasRef(alias);
SqlSelect sel = ss.Select;
sel.Selection = this.ConvertLinks(this.VisitExpression(aref));
sel.From = new SqlJoin(SqlJoinType.CrossApply, sel.From, alias, null, ss.SourceExpression);
SqlSubSelect newss = sql.SubSelect(SqlNodeType.Element, sel);
ss = newss;
}
else {
break;
}
}
return ss;
}
internal override SqlExpression VisitAliasRef(SqlAliasRef aref) {
sb.Append("AREF(");
this.WriteAliasName(aref.Alias);
sb.Append(")");
return aref;
}
internal override SqlExpression VisitAliasRef(SqlAliasRef aref) {
if (this.UnwrapSequences != null && this.UnwrapSequences.Unwrap) {
this.UnwrapSequences = new UnwrapStack(this.UnwrapSequences, false);
this.VisitAlias(aref.Alias);
this.UnwrapSequences = this.UnwrapSequences.Last;
} else {
this.VisitAlias(aref.Alias);
}
return aref;
}
