protected override Expression VisitMember(MemberExpression node)
{
if (!_translateToSql)
{
var sqlExpression = _selectExpression.GetProjectionForMemberInfo(node.Member);
if (sqlExpression != null)
{
return(BindSqlToValueBuffer(sqlExpression, node.Type));
}
if (node.Member.Name == KeyName &&
node.Expression.TryGetReferencedQuerySource() == _groupQuerySource)
{
var querySourceFinder = new QuerySourceFindingExpressionVisitor();
querySourceFinder.Visit(_keySelector);
var currentParameter = _queryModelVisitor.CurrentParameter;
foreach (var querySource in querySourceFinder.QuerySources)
{
_queryModelVisitor.QueryCompilationContext.AddOrUpdateMapping(
querySource,
currentParameter);
}
return(_projectionExpressionVisitor.Visit(_keySelector));
}
}
return(base.VisitMember(node));
}
protected override Expression VisitMember(MemberExpression memberExpression)
{
if (!_translateToSql)
{
// For composite Key case, projection member info will be already populated
var sqlExpression = _selectExpression.GetProjectionForMemberInfo(memberExpression.Member);
if (sqlExpression != null)
{
return(BindSqlToValueBuffer(sqlExpression, memberExpression.Type));
}
if (memberExpression.Member.Name == KeyName &&
memberExpression.Expression.TryGetReferencedQuerySource() == _groupQuerySource)
{
var querySourceFinder = new QuerySourceFindingExpressionVisitor();
querySourceFinder.Visit(_keySelector);
var currentParameter = _queryModelVisitor.CurrentParameter;
foreach (var querySource in querySourceFinder.QuerySources)
{
_queryModelVisitor.QueryCompilationContext.AddOrUpdateMapping(
querySource,
currentParameter);
}
sqlExpression = _projectionExpressionVisitor.Visit(_keySelector);
_sqlMapping[memberExpression] = sqlExpression;
return(sqlExpression);
}
}
return(base.VisitMember(memberExpression));
}
/// <summary>
/// Visits the given node.
/// </summary>
/// <param name="expression"> The expression to visit. </param>
/// <returns>
/// An Expression to the translated input expression.
/// </returns>
public override Expression Visit(Expression expression)
{
if (expression == null || _targetSelectExpression == null)
{
return(expression);
}
switch (expression)
{
// To save mappings so that we can compose afterwards
case NewExpression newExpression:
return(VisitNew(newExpression));
case MemberInitExpression memberInitExpression:
return(VisitMemberInit(memberInitExpression));
case QuerySourceReferenceExpression qsre:
if (_targetSelectExpression.HandlesQuerySource(qsre.ReferencedQuerySource))
{
_targetSelectExpression.ProjectStarTable
= _targetSelectExpression.GetTableForQuerySource(qsre.ReferencedQuerySource);
}
return(qsre);
// Skip over Include and Correlated Collection methods
case MethodCallExpression methodCallExpression
when IncludeCompiler.IsIncludeMethod(methodCallExpression) ||
CorrelatedCollectionOptimizingVisitor.IsCorrelatedCollectionMethod(methodCallExpression):
return(methodCallExpression);
// Group By key translation to cover composite key cases
case MemberExpression memberExpression
when memberExpression.Expression.TryGetReferencedQuerySource() == _querySource &&
_querySource.ItemType.IsGrouping() &&
memberExpression.Member.Name == nameof(IGrouping <int, int> .Key):
var groupResultOperator
= (GroupResultOperator)((SubQueryExpression)((FromClauseBase)_querySource).FromExpression)
.QueryModel.ResultOperators.Last();
var sqlTranslation
= _sqlTranslatingExpressionVisitorFactory
.Create(
QueryModelVisitor,
_isGroupAggregate ? _groupAggregateTargetSelectExpression : _targetSelectExpression,
inProjection: true)
.Visit(expression);
if (sqlTranslation == null)
{
// If the key is composite then we need to visit actual keySelector to construct the type.
// Since we are mapping translating actual KeySelector now, we need to re-map QuerySources
var querySourceFinder = new QuerySourceFindingExpressionVisitor();
querySourceFinder.Visit(groupResultOperator.KeySelector);
foreach (var querySource in querySourceFinder.QuerySources)
{
QueryModelVisitor.QueryCompilationContext.AddOrUpdateMapping(
querySource,
QueryModelVisitor.CurrentParameter);
}
_isGroupAggregate = false;
var translatedKey = Visit(groupResultOperator.KeySelector);
_isGroupAggregate = true;
return(translatedKey);
}
break;
}
// Fallback
var sqlExpression
= _sqlTranslatingExpressionVisitorFactory
.Create(
QueryModelVisitor,
_isGroupAggregate ? _groupAggregateTargetSelectExpression : _targetSelectExpression,
inProjection: true)
.Visit(expression);
if (sqlExpression == null)
{
QueryModelVisitor.RequiresClientProjection = true;
return(base.Visit(expression));
}
else if (sqlExpression is ConstantExpression &&
QueryModelVisitor.ParentQueryModelVisitor == null)
{
return(base.Visit(expression));
}
else
{
sqlExpression = sqlExpression.UnwrapNullableExpression();
// We bind with ValueBuffer in GroupByAggregate case straight away
// Since the expression can be some translation from [g].[Key] which won't bind with MemberAccessBindingEV
if (!_isGroupAggregate &&
sqlExpression is ColumnExpression)
{
var index = _targetSelectExpression.AddToProjection(sqlExpression);
_sourceExpressionProjectionMapping[expression] = _targetSelectExpression.Projection[index];
return(expression);
}
var targetExpression
= QueryModelVisitor.QueryCompilationContext.QuerySourceMapping
.GetExpression(_querySource);
if (targetExpression.Type == typeof(ValueBuffer))
{
var index = _targetSelectExpression.AddToProjection(sqlExpression);
_sourceExpressionProjectionMapping[expression] = _targetSelectExpression.Projection[index];
var readValueExpression
= _entityMaterializerSource
.CreateReadValueExpression(
targetExpression,
expression.Type.MakeNullable(),
index,
sqlExpression.FindProperty(expression.Type));
var outputDataInfo
= (expression as SubQueryExpression)?.QueryModel
.GetOutputDataInfo();
if (outputDataInfo is StreamedScalarValueInfo)
{
// Compensate for possible nulls
readValueExpression
= Expression.Coalesce(
readValueExpression,
Expression.Default(expression.Type));
}
return(Expression.Convert(readValueExpression, expression.Type));
}
return(expression);
}
}
