protected override Expression VisitOrdering(OrderingExpression orderingExpression)
{
Check.NotNull(orderingExpression, nameof(orderingExpression));
var expression = (SqlExpression)Visit(orderingExpression.Expression);
return(orderingExpression.Update(expression));
}
protected override Expression VisitOrdering(OrderingExpression orderingExpression)
{
if (orderingExpression.Expression is SqlConstantExpression ||
orderingExpression.Expression is SqlParameterExpression ||
(orderingExpression.Expression is SqlFragmentExpression sqlFragment && sqlFragment.Sql.Equals("(SELECT 1)", StringComparison.Ordinal)))
{
Sql.Append("(SELECT 1");
GeneratePseudoFromClause();
Sql.Append(")");
}
protected override Expression VisitOrdering(OrderingExpression orderingExpression)
{
// Jet uses the value -1 as True, so ordering by a boolean expression will first list the True values
// before the False values, which is the opposite of what .NET and other DBMS do, which are using 1 as True.
if (orderingExpression.Expression.TypeMapping == _boolTypeMapping)
{
orderingExpression = new OrderingExpression(
orderingExpression.Expression,
!orderingExpression.IsAscending);
}
return(base.VisitOrdering(orderingExpression));
}
/// <summary>
/// This is an internal API that supports the Entity Framework Core infrastructure and not subject to
/// the same compatibility standards as public APIs. It may be changed or removed without notice in
/// any release. You should only use it directly in your code with extreme caution and knowing that
/// doing so can result in application failures when updating to a new Entity Framework Core release.
/// </summary>
protected override Expression VisitChildren(ExpressionVisitor visitor)
{
var newOrderings = new List <OrderingExpression>();
var recreate = false;
foreach (var ordering in _orderings)
{
var newOrdering = new OrderingExpression(
(SqlExpression)visitor.Visit(ordering.Expression),
ordering.Ascending);
newOrderings.Add(newOrdering);
recreate |= newOrdering.Expression != ordering.Expression;
}
return(recreate ? new RowNumberExpression(newOrderings) : this);
}
protected override Expression VisitOrdering(OrderingExpression orderingExpression)
{
if (orderingExpression.Expression is SqlConstantExpression ||
orderingExpression.Expression is SqlParameterExpression)
{
_relationalCommandBuilder.Append("(SELECT 1)");
}
else
{
Visit(orderingExpression.Expression);
}
if (!orderingExpression.IsAscending)
{
_relationalCommandBuilder.Append(" DESC");
}
return(orderingExpression);
}
protected override Expression VisitOrdering(OrderingExpression orderingExpression)
{
if (orderingExpression.Expression is SqlConstantExpression ||
orderingExpression.Expression is SqlParameterExpression)
{
Sql.Append("(SELECT 1");
GeneratePseudoFromClause();
Sql.Append(")");
}
else
{
Visit(orderingExpression.Expression);
}
if (!orderingExpression.IsAscending)
{
Sql.Append(" DESC");
}
return(orderingExpression);
}
/// <summary> /// Visits the children of the ordering expression. /// </summary> /// <param name="orderingExpression"> The expression to visit. </param> /// <returns> The modified expression, if it or any subexpression was modified; otherwise, returns the original expression. </returns> protected abstract Expression VisitOrdering([NotNull] OrderingExpression orderingExpression);
protected abstract Expression VisitOrdering(OrderingExpression orderingExpression);
protected override Expression VisitOrdering(OrderingExpression orderingExpression)
{
var expression = (SqlExpression)Visit(orderingExpression.Expression);
return(orderingExpression.Update(expression));
}
protected override Expression VisitOrdering(OrderingExpression orderingExpression)
{
Visit(orderingExpression.Expression);
return(orderingExpression);
}
protected override Expression VisitOrdering(OrderingExpression x)
{
return(x?.Update(x.Expression.VisitNode(this)));
}
protected override Expression VisitChildren(ExpressionVisitor visitor)
{
Check.NotNull(visitor, nameof(visitor));
var changed = false;
// Note that we don't have instance functions in PG
SqlExpression[]? visitedArguments = null;
if (!IsNiladic)
{
for (var i = 0; i < Arguments.Count; i++)
{
var visitedArgument = (SqlExpression)visitor.Visit(Arguments[i]);
if (visitedArgument != Arguments[i] && visitedArguments is null)
{
changed = true;
visitedArguments = new SqlExpression[Arguments.Count];
for (var j = 0; j < visitedArguments.Length; j++)
{
visitedArguments[j] = Arguments[j];
}
}
if (visitedArguments is not null)
{
visitedArguments[i] = visitedArgument;
}
}
}
var visitedAggregatePredicate = (SqlExpression?)visitor.Visit(AggregatePredicate);
changed |= visitedAggregatePredicate != AggregatePredicate;
OrderingExpression[]? visitedAggregateOrderings = null;
for (var i = 0; i < AggregateOrderings.Count; i++)
{
var visitedOrdering = (OrderingExpression)visitor.Visit(AggregateOrderings[i]);
if (visitedOrdering != AggregateOrderings[i] && visitedAggregateOrderings is null)
{
changed = true;
visitedAggregateOrderings = new OrderingExpression[AggregateOrderings.Count];
for (var j = 0; j < visitedAggregateOrderings.Length; j++)
{
visitedAggregateOrderings[j] = AggregateOrderings[j];
}
}
if (visitedAggregateOrderings is not null)
{
visitedAggregateOrderings[i] = visitedOrdering;
}
}
return(changed
? new PostgresFunctionExpression(
Name, visitedArguments ?? Arguments, ArgumentNames, ArgumentSeparators,
IsNullable, ArgumentsPropagateNullability !,
IsAggregateDistinct,
visitedAggregatePredicate ?? AggregatePredicate,
visitedAggregateOrderings ?? AggregateOrderings,
Type, TypeMapping)
: this);
}
