internal override SqlExpression VisitMultiset(SqlSubSelect sms)
{
// allow one big-join per query?
if((this.options & SqlMultiplexerOptionType.EnableBigJoin) != 0 &&
!this.hasBigJoin && this.canJoin && this.isTopLevel && this.outerSelect != null
&& !MultisetChecker.HasMultiset(sms.Select.Selection)
&& BigJoinChecker.CanBigJoin(sms.Select))
{
sms.Select = this.VisitSelect(sms.Select);
SqlAlias alias = new SqlAlias(sms.Select);
SqlJoin join = new SqlJoin(SqlJoinType.OuterApply, this.outerSelect.From, alias, null, sms.SourceExpression);
this.outerSelect.From = @join;
this.outerSelect.OrderingType = SqlOrderingType.Always;
// make joined expression
SqlExpression expr = (SqlExpression)SqlDuplicator.Copy(sms.Select.Selection);
// make count expression
SqlSelect copySelect = (SqlSelect)SqlDuplicator.Copy(sms.Select);
SqlAlias copyAlias = new SqlAlias(copySelect);
SqlSelect countSelect = new SqlSelect(sql.Unary(SqlNodeType.Count, null, sms.SourceExpression), copyAlias, sms.SourceExpression);
countSelect.OrderingType = SqlOrderingType.Never;
SqlExpression count = sql.SubSelect(SqlNodeType.ScalarSubSelect, countSelect);
// make joined collection
SqlJoinedCollection jc = new SqlJoinedCollection(sms.ClrType, sms.SqlType, expr, count, sms.SourceExpression);
this.hasBigJoin = true;
return jc;
}
return QueryExtractor.Extract(sms, this.parentParameters);
}
internal override SqlAlias VisitAlias(SqlAlias sqlAlias) {
SqlAlias save = this.alias;
this.alias = sqlAlias;
sqlAlias.Node = this.Visit(sqlAlias.Node);
this.alias = save;
return sqlAlias;
}
internal override SqlAlias VisitAlias(SqlAlias a)
{
SqlAlias save = _currentAlias;
_currentAlias = a;
base.VisitAlias(a);
_currentAlias = save;
return a;
}
internal override SqlAlias VisitAlias(SqlAlias a)
{
SqlAlias n = new SqlAlias(a.Node);
this.nodeMap[a] = n;
n.Node = this.Visit(a.Node);
n.Name = a.Name;
return n;
}
internal SqlAliasRef(SqlAlias alias)
: base(SqlNodeType.AliasRef, GetClrType(alias.Node), alias.SourceExpression)
{
if (alias == null)
{
throw Error.ArgumentNull("alias");
}
this.alias = alias;
}
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 VisitScalarSubSelect(SqlSubSelect ss)
{
SqlSelect innerSelect = this.VisitSelect(ss.Select);
if(!this.aggregateChecker.HasAggregates(innerSelect))
{
innerSelect.Top = this.sql.ValueFromObject(1, ss.SourceExpression);
}
innerSelect.OrderingType = SqlOrderingType.Blocked;
SqlAlias alias = new SqlAlias(innerSelect);
this.currentSelect.From = new SqlJoin(SqlJoinType.OuterApply, this.currentSelect.From, alias, null, ss.SourceExpression);
return new SqlColumnRef(innerSelect.Row.Columns[0]);
}
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 SqlAlias VisitAlias(SqlAlias a)
{
SqlTable tab = a.Node as SqlTable;
SqlTableValuedFunctionCall tvf = a.Node as SqlTableValuedFunctionCall;
if(this.addPrimaryKeys && (tab != null || tvf != null))
{
List<SqlOrderExpression> list = new List<SqlOrderExpression>();
bool isTable = tab != null;
MetaType rowType = isTable ? tab.RowType : tvf.RowType;
foreach(MetaDataMember mm in rowType.IdentityMembers)
{
string name = mm.MappedName;
SqlColumn col;
Expression sourceExpression;
List<SqlColumn> columns;
if(isTable)
{
col = tab.Find(name);
sourceExpression = tab.SourceExpression;
columns = tab.Columns;
}
else
{
col = tvf.Find(name);
sourceExpression = tvf.SourceExpression;
columns = tvf.Columns;
}
if(col == null)
{
col = new SqlColumn(mm.MemberAccessor.Type, typeProvider.From(mm.MemberAccessor.Type), name, mm, null, sourceExpression);
col.Alias = a;
columns.Add(col);
}
list.Add(new SqlOrderExpression(SqlOrderType.Ascending, new SqlColumnRef(col)));
}
this.PrependOrderExpressions(list);
return a;
}
else
{
return base.VisitAlias(a);
}
}
internal SqlAlias VisitAliasConsumed(SqlAlias a) {
if (a == null)
return a;
bool match = false;
foreach (SqlAlias alias in aliases)
if (alias == a) {
match = true;
break;
}
if (match) {
this.referencesAnyMatchingAliases = true;
}
return a;
}
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);
_parameterExpressionToSqlExpression[outerKeySelector.Parameters[0]] = outerRef;
SqlExpression outerKey = this.VisitExpression(outerKeySelector.Body);
_parameterExpressionToSqlExpression[innerKeySelector.Parameters[0]] = innerRef;
SqlExpression innerKey = this.VisitExpression(innerKeySelector.Body);
_parameterExpressionToSqlExpression[resultSelector.Parameters[0]] = outerRef;
_parameterExpressionToSqlExpression[resultSelector.Parameters[1]] = innerRef;
SqlExpression result = this.VisitExpression(resultSelector.Body);
SqlExpression condition = _nodeFactory.Binary(SqlNodeType.EQ, outerKey, innerKey);
SqlSelect select = null;
if((_converterStrategy & ConverterStrategy.CanUseJoinOn) != 0)
{
SqlJoin join = new SqlJoin(SqlJoinType.Inner, outerAlias, innerAlias, condition, _dominatingExpression);
select = new SqlSelect(result, join, _dominatingExpression);
}
else
{
SqlJoin join = new SqlJoin(SqlJoinType.Cross, outerAlias, innerAlias, null, _dominatingExpression);
select = new SqlSelect(result, join, _dominatingExpression);
select.Where = condition;
}
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);
_parameterExpressionToSqlExpression[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, _dominatingExpression);
SqlExpression projection = selRef;
if(resultSelector != null)
{
_parameterExpressionToSqlExpression[resultSelector.Parameters[0]] = seqRef;
_parameterExpressionToSqlExpression[resultSelector.Parameters[1]] = selRef;
projection = this.VisitExpression(resultSelector.Body);
}
return new SqlSelect(projection, join, _dominatingExpression);
}
private SqlSelect VisitSelect(Expression sequence, LambdaExpression selector)
{
SqlSelect source = this.VisitSequence(sequence);
SqlAlias alias = new SqlAlias(source);
SqlAliasRef aref = new SqlAliasRef(alias);
_parameterExpressionToSqlExpression[selector.Parameters[0]] = aref;
SqlNode project = this.Visit(selector.Body);
SqlSelect pselect = project as SqlSelect;
if(pselect != null)
{
return new SqlSelect(_nodeFactory.SubSelect(SqlNodeType.Multiset, pselect, selector.Body.Type), alias, _dominatingExpression);
}
else if((project.NodeType == SqlNodeType.Element || project.NodeType == SqlNodeType.ScalarSubSelect) &&
(_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",
_nodeFactory.Unary(
SqlNodeType.OuterJoinedValue,
_nodeFactory.Value(typeof(int?), _typeProvider.From(typeof(int)), 1, false, _dominatingExpression)
)
),
_nodeFactory.Unary(SqlNodeType.OuterJoinedValue, inner.Selection)
);
}
else
{
inner.Selection = _nodeFactory.Unary(SqlNodeType.OuterJoinedValue, inner.Selection);
}
SqlJoin join = new SqlJoin(SqlJoinType.OuterApply, alias, innerAlias, null, _dominatingExpression);
return new SqlSelect(innerRef, join, _dominatingExpression);
}
else
{
SqlExpression expr = project as SqlExpression;
if(expr != null)
{
return new SqlSelect(expr, alias, _dominatingExpression);
}
else
{
throw Error.BadProjectionInSelect();
}
}
}
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, _dominatingExpression);
}
return select;
}
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, _dominatingExpression);
}
return sel;
}
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", _nodeFactory.RowNumber(new List<SqlOrderExpression>(), _dominatingExpression));
SqlColumnRef rowNumberRef = new SqlColumnRef(rowNumber);
select.Row.Columns.Add(rowNumber);
SqlSelect final = new SqlSelect(aref, alias, _dominatingExpression);
if(takeExp != null)
{
// use BETWEEN for skip+take combo (much faster)
final.Where = _nodeFactory.Between(
rowNumberRef,
_nodeFactory.Add(skipExp, 1),
_nodeFactory.Binary(SqlNodeType.Add, (SqlExpression)SqlDuplicator.Copy(skipExp), takeExp),
_dominatingExpression
);
}
else
{
final.Where = _nodeFactory.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, _dominatingExpression);
eqsel.Where = _nodeFactory.Binary(SqlNodeType.EQ2V, aref, dupRef);
SqlSubSelect ss = _nodeFactory.SubSelect(SqlNodeType.Exists, eqsel);
SqlSelect final = new SqlSelect(aref, alias, _dominatingExpression);
final.Where = _nodeFactory.Unary(SqlNodeType.Not, ss, _dominatingExpression);
final.Top = takeExp;
return final;
}
}
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)
_parameterExpressionToSqlExpression[lambda.Parameters[0]] = aref;
if(_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,
_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
_parameterExpressionToSqlExpression[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, _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,
_dominatingExpression
);
sel.Where = isCount ? exp : null;
return _nodeFactory.SubSelect(SqlNodeType.ScalarSubSelect, sel);
}
}
private SqlNode VisitQuantifier(SqlSelect select, LambdaExpression lambda, bool isAny)
{
SqlAlias alias = new SqlAlias(select);
SqlAliasRef aref = new SqlAliasRef(alias);
if(lambda != null)
{
_parameterExpressionToSqlExpression[lambda.Parameters[0]] = aref;
}
SqlExpression cond = lambda != null ? this.VisitExpression(lambda.Body) : null;
return this.GenerateQuantifier(alias, cond, isAny);
}
internal void VisitAliasConsumed(SqlAlias a)
{
_consumed.Add(a);
}
private void WriteAliasName(SqlAlias alias)
{
string aliasName = null;
if(alias.Name == null)
{
if(!_names.TryGetValue(alias, out aliasName))
{
aliasName = "A" + _names.Count;
_names[alias] = aliasName;
}
}
else
{
aliasName = alias.Name;
}
this.WriteName(aliasName);
}
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, _nodeFactory.Binary(SqlNodeType.EQ2V, aref1, aref2), true);
SqlSelect result = new SqlSelect(aref1, alias1, select1.SourceExpression);
result.Where = _nodeFactory.Unary(SqlNodeType.Not, any);
result.IsDistinct = true;
result.OrderingType = SqlOrderingType.Blocked;
return result;
}
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, _dominatingExpression);
result.OrderingType = SqlOrderingType.Blocked;
return result;
}
/// <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 = _nodeFactory.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 = _translator.BuildProjection(aref, function.ResultRowTypes[0].InheritanceRoot, _allowDeferred, null, mce);
SqlSelect select = new SqlSelect(projection, alias, mce);
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);
_parameterExpressionToSqlExpression[outerKeySelector.Parameters[0]] = outerRef;
SqlExpression outerKey = this.VisitExpression(outerKeySelector.Body);
_parameterExpressionToSqlExpression[innerKeySelector.Parameters[0]] = innerRef;
SqlExpression innerKey = this.VisitExpression(innerKeySelector.Body);
// make multiset
SqlExpression pred = _nodeFactory.Binary(SqlNodeType.EQ, outerKey, innerKey);
SqlSelect select = new SqlSelect(innerRef, innerAlias, _dominatingExpression);
select.Where = pred;
SqlSubSelect subquery = _nodeFactory.SubSelect(SqlNodeType.Multiset, select);
// make outer ref & multiset for result-selector params
_parameterExpressionToSqlExpression[resultSelector.Parameters[0]] = outerRef;
_parameterExpressionToSqlNode[resultSelector.Parameters[1]] = subquery;
SqlExpression result = this.VisitExpression(resultSelector.Body);
return new SqlSelect(result, outerAlias, _dominatingExpression);
}
private SqlExpression GenerateQuantifier(SqlAlias alias, SqlExpression cond, bool isAny)
{
SqlAliasRef aref = new SqlAliasRef(alias);
if(isAny)
{
SqlSelect sel = new SqlSelect(aref, alias, _dominatingExpression);
sel.Where = cond;
sel.OrderingType = SqlOrderingType.Never;
SqlSubSelect exists = _nodeFactory.SubSelect(SqlNodeType.Exists, sel);
return exists;
}
else
{
SqlSelect sel = new SqlSelect(aref, alias, _dominatingExpression);
SqlSubSelect ss = _nodeFactory.SubSelect(SqlNodeType.Exists, sel);
sel.Where = _nodeFactory.Unary(SqlNodeType.Not2V, cond, _dominatingExpression);
return _nodeFactory.Unary(SqlNodeType.Not, ss, _dominatingExpression);
}
}
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",
_nodeFactory.Unary(SqlNodeType.OuterJoinedValue,
_nodeFactory.Value(typeof(int?), _typeProvider.From(typeof(int)), 1, false, _dominatingExpression)
)
),
_nodeFactory.Unary(SqlNodeType.OuterJoinedValue, aliasRef)
);
SqlSelect optSelect = new SqlSelect(opt, alias, _dominatingExpression);
alias = new SqlAlias(optSelect);
aliasRef = new SqlAliasRef(alias);
SqlExpression litNull = _nodeFactory.TypedLiteralNull(typeof(string), _dominatingExpression);
SqlSelect selNull = new SqlSelect(litNull, null, _dominatingExpression);
SqlAlias aliasNull = new SqlAlias(selNull);
SqlJoin join = new SqlJoin(SqlJoinType.OuterApply, aliasNull, alias, null, _dominatingExpression);
return new SqlSelect(aliasRef, join, _dominatingExpression);
}
private SqlStatement VisitInsert(Expression item, LambdaExpression resultSelector)
{
if(item == null)
{
throw Error.ArgumentNull("item");
}
_dominatingExpression = item;
MetaTable metaTable = _services.Model.GetTable(item.Type);
Expression source = _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 = _nodeFactory.ValueFromObject(conItem.Value, true, source);
foreach(MetaDataMember mm in itemMetaType.PersistentDataMembers)
{
if(!mm.IsAssociation && !mm.IsDbGenerated && !mm.IsVersion)
{
bindings.Add(new SqlMemberAssign(mm.Member, _nodeFactory.Member(sqlExprItem, mm.Member)));
}
}
ConstructorInfo cons = itemMetaType.Type.GetConstructor(Type.EmptyTypes);
System.Diagnostics.Debug.Assert(cons != null);
sqlItem = _nodeFactory.New(itemMetaType, cons, null, null, bindings, item);
SqlTable tab = _nodeFactory.Table(metaTable, metaTable.RowType, _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) && (_converterStrategy & ConverterStrategy.CanOutputFromInsert) != 0)
{
sin.OutputKey = new SqlColumn(id.Type, _nodeFactory.Default(id), id.Name, id, null, _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);
_parameterExpressionToSqlExpression.Add(resultSelector.Parameters[0], tableAliasRef);
SqlExpression projection = this.VisitExpression(resultSelector.Body);
// build select to return result
SqlExpression pred = null;
if(id != null)
{
pred = _nodeFactory.Binary(
SqlNodeType.EQ,
_nodeFactory.Member(tableAliasRef, id.Member),
this.GetIdentityExpression(id, sin.OutputKey != null)
);
}
else
{
SqlExpression itemExpression = this.VisitExpression(item);
pred = _nodeFactory.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 = _nodeFactory.Default(id);
exp = _nodeFactory.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);
_parameterExpressionToSqlExpression.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(_dominatingExpression);
block.Statements.Add(sin);
if(preResult != null)
{
block.Statements.Add(preResult);
}
block.Statements.Add(result);
return block;
}
}
private SqlSelect VisitOrderBy(Expression sequence, LambdaExpression expression, SqlOrderType orderType)
{
if(IsGrouping(expression.Body.Type))
{
throw Error.GroupingNotSupportedAsOrderCriterion();
}
if(!_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, _dominatingExpression);
}
_parameterExpressionToSqlExpression[expression.Parameters[0]] = (SqlAliasRef)select.Selection;
SqlExpression expr = this.VisitExpression(expression.Body);
select.OrderBy.Add(new SqlOrderExpression(orderType, expr));
return select;
}
internal SqlAliasRef(SqlAlias alias)
: base(SqlNodeType.AliasRef, GetClrType(alias.Node), alias.SourceExpression) {
if (alias == null)
throw Error.ArgumentNull("alias");
this.alias = alias;
}
internal virtual SqlAlias VisitAlias(SqlAlias a) {
a.Node = this.Visit(a.Node);
return a;
}
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
_parameterExpressionToSqlExpression[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);
_parameterExpressionToSqlExpression[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
_parameterExpressionToSqlExpression[elemLambda.Parameters[0]] = selDupRef;
elemExpr = this.VisitExpression(elemLambda.Body);
// evaluate element expression relative to original sequence
_parameterExpressionToSqlExpression[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, _dominatingExpression);
selElem.Where = _nodeFactory.Binary(SqlNodeType.EQ2V, keyExpr, keyDup);
// Finally, make the MULTISET node. this will be used as part of the final select
SqlSubSelect ss = _nodeFactory.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, _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, _typeProvider.From(elementType), keyExpr, ss, _dominatingExpression);
SqlSelect keyGroupSel = new SqlSelect(keyGroup, gselAlias, _dominatingExpression);
SqlAlias kgAlias = new SqlAlias(keyGroupSel);
SqlAliasRef kgAliasRef = new SqlAliasRef(kgAlias);
_parameterExpressionToSqlExpression[resultSelector.Parameters[0]] = _nodeFactory.Member(kgAliasRef, elementType.GetProperty("Key"));
_parameterExpressionToSqlExpression[resultSelector.Parameters[1]] = kgAliasRef;
// remember the select that has the actual group (for optimizing aggregates later)
_sqlNodeToGroupInfo[kgAliasRef] = new GroupInfo { SelectWithGroup = gsel, ElementOnGroupSource = elemOnGroupSource };
SqlExpression resultExpr = this.VisitExpression(resultSelector.Body);
result = new SqlSelect(resultExpr, kgAlias, _dominatingExpression);
// remember the select that has the actual group (for optimizing aggregates later)
_sqlNodeToGroupInfo[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, _typeProvider.From(elementType), keyExpr, ss, _dominatingExpression);
result = new SqlSelect(resultExpr, gselAlias, _dominatingExpression);
// remember the select that has the actual group (for optimizing aggregates later)
_sqlNodeToGroupInfo[resultExpr] = new GroupInfo { SelectWithGroup = gsel, ElementOnGroupSource = elemOnGroupSource };
}
return result;
}
