/// <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 (_topLevelProjection &&
(QueryModelVisitor.Expression as MethodCallExpression)?.Method.MethodIsClosedFormOf(
QueryModelVisitor.QueryCompilationContext.QueryMethodProvider.GroupByMethod) == true)
{
var translation = new GroupByAggregateTranslatingExpressionVisitor(this)
.Translate(expression);
if (translation != null)
{
QueryModelVisitor.RequiresStreamingGroupResultOperator = false;
return(translation);
}
}
_topLevelProjection = false;
var selectExpression = QueryModelVisitor.TryGetQuery(_querySource);
if (expression != null &&
!(expression is ConstantExpression) &&
!(expression is NewExpression) &&
!(expression is MemberInitExpression) &&
selectExpression != null)
{
var existingProjectionsCount = selectExpression.Projection.Count;
var sqlExpression
= _sqlTranslatingExpressionVisitorFactory
.Create(QueryModelVisitor, selectExpression, inProjection: true)
.Visit(expression);
if (sqlExpression == null)
{
switch (expression)
{
case MethodCallExpression methodCallExpression when IncludeCompiler.IsIncludeMethod(methodCallExpression):
return(base.Visit(expression));
case QuerySourceReferenceExpression qsre:
if (QueryModelVisitor.ParentQueryModelVisitor != null &&
selectExpression.HandlesQuerySource(qsre.ReferencedQuerySource))
{
selectExpression.ProjectStarTable = selectExpression.GetTableForQuerySource(qsre.ReferencedQuerySource);
}
break;
default:
QueryModelVisitor.RequiresClientProjection = true;
break;
}
}
else
{
selectExpression.RemoveRangeFromProjection(existingProjectionsCount);
if (!(expression is QuerySourceReferenceExpression))
{
if (sqlExpression is NullableExpression nullableExpression)
{
sqlExpression = nullableExpression.Operand;
}
if (sqlExpression is ColumnExpression)
{
var index = selectExpression.AddToProjection(sqlExpression);
_sourceExpressionProjectionMapping[expression] = selectExpression.Projection[index];
return(expression);
}
}
if (!(sqlExpression is ConstantExpression))
{
var targetExpression
= QueryModelVisitor.QueryCompilationContext.QuerySourceMapping
.GetExpression(_querySource);
if (targetExpression.Type == typeof(ValueBuffer))
{
var index = selectExpression.AddToProjection(sqlExpression);
_sourceExpressionProjectionMapping[expression] = selectExpression.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);
}
}
}
return(base.Visit(expression));
}
/// <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 (_topLevelProjection &&
(QueryModelVisitor.Expression as MethodCallExpression)?.Method.MethodIsClosedFormOf(
QueryModelVisitor.QueryCompilationContext.QueryMethodProvider.GroupByMethod) == true)
{
var translation = new GroupByAggregateTranslatingExpressionVisitor(this)
.Translate(expression);
if (translation != null)
{
QueryModelVisitor.RequiresStreamingGroupResultOperator = false;
return(translation);
}
}
_topLevelProjection = false;
if (expression == null || _selectExpression == null)
{
return(expression);
}
switch (expression)
{
case ConstantExpression constantExpression:
return(constantExpression);
// 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 (_selectExpression.HandlesQuerySource(qsre.ReferencedQuerySource))
{
_selectExpression.ProjectStarTable
= _selectExpression.GetTableForQuerySource(qsre.ReferencedQuerySource);
}
return(qsre);
// Skip over Include method
case MethodCallExpression methodCallExpression when IncludeCompiler.IsIncludeMethod(methodCallExpression):
return(methodCallExpression);
default:
var sqlExpression
= _sqlTranslatingExpressionVisitorFactory
.Create(QueryModelVisitor, _selectExpression, inProjection: true)
.Visit(expression);
if (sqlExpression == null)
{
QueryModelVisitor.RequiresClientProjection = true;
return(base.Visit(expression));
}
else if (sqlExpression is ConstantExpression)
{
return(base.Visit(expression));
}
else
{
if (sqlExpression is NullableExpression nullableExpression)
{
sqlExpression = nullableExpression.Operand;
}
if (sqlExpression is ColumnExpression)
{
var index = _selectExpression.AddToProjection(sqlExpression);
_sourceExpressionProjectionMapping[expression] = _selectExpression.Projection[index];
return(expression);
}
var targetExpression
= QueryModelVisitor.QueryCompilationContext.QuerySourceMapping
.GetExpression(_querySource);
if (targetExpression.Type == typeof(ValueBuffer))
{
var index = _selectExpression.AddToProjection(sqlExpression);
_sourceExpressionProjectionMapping[expression] = _selectExpression.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);
}
}
}
