protected override Expression VisitSelect(SqlSelectExpression selectExpression)
{
if (this.currentProjection == null || this.currentProjection.Select != selectExpression)
{
return(base.VisitSelect(selectExpression));
}
var objectType = selectExpression.Type.GetSequenceElementType();
if (!objectType.IsDataAccessObjectType())
{
return(base.VisitSelect(selectExpression));
}
var aliasesAndTypes = SqlAliasTypeCollector.Collect(selectExpression)
.ToDictionary(c => c.Item1, c => typeDescriptorProvider.GetTypeDescriptor(c.Item2.GetSequenceElementType() ?? c.Item2));
List <SqlOrderByExpression> orderBys = null;
var includeJoins = selectExpression.From.GetIncludeJoins().ToList();
List <SqlColumnExpression> leftMostColumns = null;
foreach (var includeJoin in includeJoins)
{
var equalsExpression = (BinaryExpression)SqlExpressionFinder.FindFirst(includeJoin, c => c.NodeType == ExpressionType.Equal);
var left = (SqlColumnExpression)equalsExpression.Left;
var right = (SqlColumnExpression)equalsExpression.Right;
var leftType = aliasesAndTypes[left.SelectAlias];
var rightType = aliasesAndTypes[right.SelectAlias];
if (leftMostColumns == null)
{
var typeDescriptor = this.typeDescriptorProvider.GetTypeDescriptor(objectType);
var primaryKeyColumns = new HashSet <string>(QueryBinder.GetPrimaryKeyColumnInfos(this.typeDescriptorProvider, typeDescriptor).Select(c => c.ColumnName));
leftMostColumns = primaryKeyColumns
.Select(c => new SqlColumnExpression(objectType, left.SelectAlias, c))
.ToList();
}
var rightProperty = rightType.GetPropertyDescriptorByColumnName(right.Name);
var leftProperty = rightProperty.RelationshipInfo?.TargetProperty ?? leftType.GetPropertyDescriptorByColumnName(left.Name);
if (leftProperty.PropertyType.GetGenericTypeDefinitionOrNull() == typeof(RelatedDataAccessObjects <>))
{
var rightColumns = SqlExpressionFinder.FindAll(includeJoin, c => c.NodeType == (ExpressionType)SqlExpressionType.Column && ((SqlColumnExpression)c).SelectAlias == right.SelectAlias);
var leftColumns = SqlExpressionFinder.FindAll(includeJoin, c => c.NodeType == (ExpressionType)SqlExpressionType.Column && ((SqlColumnExpression)c).SelectAlias == left.SelectAlias);
if (orderBys == null)
{
orderBys = new List <SqlOrderByExpression>();
if (selectExpression.OrderBy?.Count > 0)
{
orderBys.AddRange(selectExpression.OrderBy);
orderBys.AddRange(leftMostColumns.Select(c => new SqlOrderByExpression(OrderType.Ascending, c)));
}
}
orderBys.AddRange(rightColumns.Select(c => new SqlOrderByExpression(OrderType.Ascending, c)));
orderBys.AddRange(leftColumns.Select(c => new SqlOrderByExpression(OrderType.Ascending, c)));
}
}
return(selectExpression.ChangeOrderBy(orderBys?.Distinct(SqlExpressionEqualityComparer <SqlOrderByExpression> .Default) ?? selectExpression.OrderBy));
}
