protected virtual Expression BindOrderBy(Type resultType, Expression source, LambdaExpression orderSelector, DbOrderType orderType)
{
List <DbOrderExpression> myThenBys = this.thenBys;
this.thenBys = null;
DbProjectionExpression projection = this.VisitSequence(source);
this.map[orderSelector.Parameters[0]] = projection.Projector;
List <DbOrderExpression> orderings = new List <DbOrderExpression>();
orderings.Add(new DbOrderExpression(orderType, this.Visit(orderSelector.Body)));
if (myThenBys != null)
{
for (int i = myThenBys.Count - 1; i >= 0; i--)
{
DbOrderExpression tb = myThenBys[i];
LambdaExpression lambda = (LambdaExpression)tb.Expression;
this.map[lambda.Parameters[0]] = projection.Projector;
orderings.Add(new DbOrderExpression(tb.OrderType, this.Visit(lambda.Body)));
}
}
var alias = this.GetNextAlias();
ProjectedColumns pc = this.ProjectColumns(projection.Projector, alias, projection.Select.Alias);
return(new DbProjectionExpression(
new DbSelectExpression(alias, pc.Columns, projection.Select, null, orderings.AsReadOnly(), null),
pc.Projector
));
}
protected virtual ReadOnlyCollection <DbOrderExpression> VisitOrderBy(
ReadOnlyCollection <DbOrderExpression> expressions)
{
if (expressions != null)
{
List <DbOrderExpression> alternate = null;
for (int i = 0, n = expressions.Count; i < n; i++)
{
DbOrderExpression expr = expressions[i];
Expression e = Visit(expr.Expression);
if (alternate == null && e != expr.Expression)
{
alternate = expressions.Take(i).ToList();
}
if (alternate != null)
{
alternate.Add(new DbOrderExpression(expr.OrderType, e));
}
}
if (alternate != null)
{
return(alternate.AsReadOnly());
}
}
return(expressions);
}
public static DbSelectExpression AddOrderExpression(this DbSelectExpression select, DbOrderExpression ordering)
{
List <DbOrderExpression> orderby = new List <DbOrderExpression>();
if (select.OrderBy != null)
{
orderby.AddRange(select.OrderBy);
}
orderby.Add(ordering);
return(select.SetOrderBy(orderby));
}
public static DbSelectExpression RemoveOrderExpression(this DbSelectExpression select, DbOrderExpression ordering)
{
if (select.OrderBy != null && select.OrderBy.Count > 0)
{
List <DbOrderExpression> orderby = new List <DbOrderExpression>(select.OrderBy);
orderby.Remove(ordering);
return(select.SetOrderBy(orderby));
}
return(select);
}
public static DbSelectExpression RemoveOrderExpression(this DbSelectExpression select, DbOrderExpression ordering)
{
if (select.OrderBy != null && select.OrderBy.Count > 0)
{
List<DbOrderExpression> orderby = new List<DbOrderExpression>(select.OrderBy);
orderby.Remove(ordering);
return select.SetOrderBy(orderby);
}
return select;
}
public static DbSelectExpression AddOrderExpression(this DbSelectExpression select, DbOrderExpression ordering)
{
List<DbOrderExpression> orderby = new List<DbOrderExpression>();
if (select.OrderBy != null)
orderby.AddRange(select.OrderBy);
orderby.Add(ordering);
return select.SetOrderBy(orderby);
}
